Fixed history DTO view

Add track, release, and queue sharing with post-login redirects; support shared playlist links and highlighted shared tracks.

Add local synchronized playback for jams, constrain HTTP metrics to known routes, and refine mobile player controls/layout.

.gitignore

@@ -2,3 +2,4 @@
 /nul
 /.claude
 /media
+/federation

Cargo.toml

@@ -1,17 +1,24 @@
 [package]
 name = "furumusic"
-version = "0.2.10"
+version = "0.9.6"
 edition = "2024"
 description = "Reusable web-app boilerplate: auth, OIDC/SSO, admin panel, user management, i18n, PostgreSQL"
 
 [dependencies]
-cot = { version = "0.6.0", features = ["postgres", "json", "openapi", "swagger-ui"] }
+# default-features off: cot's defaults include the sqlite backend, whose old
+# libsqlite3-sys collides with music-dht's rusqlite (one native sqlite3 per
+# binary). This server only ever talks PostgreSQL.
+cot = { version = "0.6.0", default-features = false, features = ["postgres", "json", "openapi", "swagger-ui"] }
 schemars = { version = "0.9", features = ["derive"] }
 serde = { version = "1", features = ["derive"] }
 openidconnect = "4.0"
 reqwest = { version = "0.12", default-features = false, features = ["rustls-tls", "json"] }
 tokio = { version = "1", features = ["sync", "fs", "io-util"] }
+async-stream = "0.3"
+bytes = "1"
+tower = "0.5"
 base64 = "0.22"
+blake3 = "1"
 serde_json = "1"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
@@ -27,5 +34,9 @@ anyhow = "1.0"
 tokio-cron-scheduler = "0.15"
 croner = "3"
 async-trait = "0.1"
+postcard = { version = "1", features = ["alloc"] }
 uuid = "1"
 librqbit = { version = "8.1.1", features = ["disable-upload"] }
+# P2P federation: publishes the library into a shared DHT and serves audio /
+# catalogs to furumi peers (TUI clients) over the frid stack.
+music-dht = { git = "https://gt.hexor.cy/ab/frid.git" }

src/admin/mod.rs

@@ -227,6 +227,55 @@ impl App for AdminApp {
                 },
                 "admin_v2_reviews_bulk",
             ),
+            Route::with_handler_and_name(
+                "/v2/api/users",
+                {
+                    let pool = Arc::clone(&pool);
+                    let pool_config = Arc::clone(&pool_config);
+                    get(move |session: Session, db: Database,
+                              query: UrlQuery<v2::UsersQuery>| {
+                        let pool = Arc::clone(&pool);
+                        let pool_config = Arc::clone(&pool_config);
+                        async move {
+                            let pg_pool = pool
+                                .get_or_init(|| async {
+                                    sqlx::postgres::PgPoolOptions::new()
+                                        .max_connections(5)
+                                        .connect(&pool_config.database_url)
+                                        .await
+                                        .expect("admin pool")
+                                })
+                                .await;
+                            v2::users(session, db, pg_pool, query.0).await
+                        }
+                    })
+                },
+                "admin_v2_users",
+            ),
+            Route::with_handler_and_name(
+                "/v2/api/users/{id}",
+                {
+                    let pool = Arc::clone(&pool);
+                    let pool_config = Arc::clone(&pool_config);
+                    get(move |session: Session, db: Database, path: Path<PathId>| {
+                        let pool = Arc::clone(&pool);
+                        let pool_config = Arc::clone(&pool_config);
+                        async move {
+                            let pg_pool = pool
+                                .get_or_init(|| async {
+                                    sqlx::postgres::PgPoolOptions::new()
+                                        .max_connections(5)
+                                        .connect(&pool_config.database_url)
+                                        .await
+                                        .expect("admin pool")
+                                })
+                                .await;
+                            v2::user_detail(session, db, pg_pool, path.0.id).await
+                        }
+                    })
+                },
+                "admin_v2_user_detail",
+            ),
             Route::with_handler_and_name(
                 "/v2/api/reviews/{id}/approve",
                 {
@@ -308,6 +357,32 @@ impl App for AdminApp {
                 }),
                 "admin_v2_metadata_backfill_run_options",
             ),
+            Route::with_handler_and_name(
+                "/v2/api/jobs/artwork_backfill/run-options",
+                cot::router::method::post({
+                    let pool = Arc::clone(&pool);
+                    let pool_config = Arc::clone(&pool_config);
+                    move |session: Session,
+                          db: Database,
+                          json: Json<v2::ArtworkBackfillRunRequest>| {
+                        let pool = Arc::clone(&pool);
+                        let pool_config = Arc::clone(&pool_config);
+                        async move {
+                            let pg_pool = pool
+                                .get_or_init(|| async {
+                                    sqlx::postgres::PgPoolOptions::new()
+                                        .max_connections(5)
+                                        .connect(&pool_config.database_url)
+                                        .await
+                                        .expect("admin pool")
+                                })
+                                .await;
+                            v2::run_artwork_backfill(session, db, pg_pool, json).await
+                        }
+                    }
+                }),
+                "admin_v2_artwork_backfill_run_options",
+            ),
             Route::with_handler_and_name(
                 "/v2/api/jobs/{name}/run",
                 cot::router::method::post({
@@ -340,6 +415,38 @@ impl App for AdminApp {
                 }),
                 "admin_v2_settings_probe",
             ),
+            Route::with_handler_and_name(
+                "/v2/api/federation",
+                get(move |session: Session, db: Database| async move {
+                    v2::federation_status(session, db).await
+                }),
+                "admin_v2_federation_status",
+            ),
+            Route::with_handler_and_name(
+                "/v2/api/federation/sync",
+                cot::router::method::post(move |session: Session, db: Database| async move {
+                    v2::federation_sync(session, db).await
+                }),
+                "admin_v2_federation_sync",
+            ),
+            Route::with_handler_and_name(
+                "/v2/api/federation/ticket",
+                get(move |session: Session, db: Database| async move {
+                    v2::federation_ticket(session, db).await
+                }),
+                "admin_v2_federation_ticket",
+            ),
+            Route::with_handler_and_name(
+                "/v2/api/federation/connect",
+                cot::router::method::post(
+                    move |session: Session,
+                          db: Database,
+                          json: Json<v2::FederationConnectRequest>| async move {
+                        v2::federation_connect(session, db, json).await
+                    },
+                ),
+                "admin_v2_federation_connect",
+            ),
             Route::with_handler_and_name(
                 "/v2/api/jobs/{name}/toggle",
                 cot::router::method::post({
@@ -480,6 +587,32 @@ impl App for AdminApp {
                 },
                 "admin_v2_library_item_detail",
             ),
+            Route::with_handler_and_name(
+                "/v2/api/library/tracks/search",
+                {
+                    let pool = Arc::clone(&pool);
+                    let pool_config = Arc::clone(&pool_config);
+                    get(move |session: Session,
+                              db: Database,
+                              query: UrlQuery<v2::TrackSearchQuery>| {
+                        let pool = Arc::clone(&pool);
+                        let pool_config = Arc::clone(&pool_config);
+                        async move {
+                            let pg_pool = pool
+                                .get_or_init(|| async {
+                                    sqlx::postgres::PgPoolOptions::new()
+                                        .max_connections(5)
+                                        .connect(&pool_config.database_url)
+                                        .await
+                                        .expect("admin pool")
+                                })
+                                .await;
+                            v2::track_search(session, db, pg_pool, query.0).await
+                        }
+                    })
+                },
+                "admin_v2_library_tracks_search",
+            ),
             Route::with_handler_and_name(
                 "/v2/api/library/item/image",
                 {
@@ -1249,6 +1382,9 @@ impl App for AdminApp {
         all.extend(cot::db::migrations::wrap_migrations(
             crate::scheduler::db_migrations::MIGRATIONS,
         ));
+        all.extend(cot::db::migrations::wrap_migrations(
+            crate::auth::db_migrations::MIGRATIONS,
+        ));
         all
     }
 }

src/admin/views.rs

@@ -1472,6 +1472,7 @@ pub async fn metadata_backfill_run(
         duration_seconds: data.duration_seconds.is_some(),
         local_genres: data.local_genres.is_some(),
         lastfm_tags: data.lastfm_tags.is_some(),
+        musicbrainz_tags: true,
         overwrite: data.mode.as_deref() == Some("overwrite"),
     };
 

src/agent/cover_art.rs

@@ -128,13 +128,21 @@ pub async fn find_best_cover(folder: &Path, audio_files: &[PathBuf]) -> Option<C
         match tokio::fs::read(img_path).await {
             Ok(data) if !data.is_empty() => {
                 let mime = mime_for_image(img_path);
+                crate::metrics::record_agent_cover_lookup("folder", "ok", data.len());
                 return Some(CoverImage {
                     data,
                     mime_type: mime,
                     source: CoverSource::FolderFile(img_path.clone()),
                 });
             }
-            _ => continue,
+            Ok(_) => {
+                crate::metrics::record_agent_cover_lookup("folder", "empty", 0);
+                continue;
+            }
+            Err(_) => {
+                crate::metrics::record_agent_cover_lookup("folder", "error", 0);
+                continue;
+            }
         }
     }
 
@@ -143,10 +151,12 @@ pub async fn find_best_cover(folder: &Path, audio_files: &[PathBuf]) -> Option<C
         let path = audio_path.to_path_buf();
         let result = tokio::task::spawn_blocking(move || extract_embedded_cover(&path)).await;
         if let Ok(Some(cover)) = result {
+            crate::metrics::record_agent_cover_lookup("embedded", "ok", cover.data.len());
             return Some(cover);
         }
     }
 
+    crate::metrics::record_agent_cover_lookup("none", "not_found", 0);
     None
 }
 

src/agent/cover_variants.rs

@@ -74,6 +74,7 @@ fn generate_missing_variants_sync(
 
     let mut created = 0usize;
     for variant in variants {
+        let start = std::time::Instant::now();
         let path = variant_path(original_path, *variant);
         if path.exists() {
             continue;
@@ -88,12 +89,21 @@ fn generate_missing_variants_sync(
             .to_rgb8();
         let mut output = Vec::new();
         let mut encoder = JpegEncoder::new_with_quality(&mut output, variant.quality);
-        encoder.encode(
+        let result = encoder.encode(
             &resized,
             resized.width(),
             resized.height(),
             image::ExtendedColorType::Rgb8,
-        )?;
+        );
+        match result {
+            Ok(()) => {
+                crate::metrics::record_agent_cover_variant(variant.name, "ok", start.elapsed())
+            }
+            Err(err) => {
+                crate::metrics::record_agent_cover_variant(variant.name, "error", start.elapsed());
+                return Err(err.into());
+            }
+        }
         std::fs::write(path, output)?;
         created += 1;
     }

src/agent/normalize.rs

@@ -330,6 +330,7 @@ pub async fn normalize_batch(
     // If over 80% of context limit and more than 1 file, split
     let limit_80 = context_limit * 80 / 100;
     if estimated > limit_80 && files.len() > 1 {
+        crate::metrics::record_agent_llm_split("estimated_context");
         tracing::info!(
             estimated_tokens = estimated,
             context_limit,
@@ -419,6 +420,7 @@ pub async fn normalize_batch(
                 || err_str.contains("length")
                 || err_str.contains("token");
             if is_context_error {
+                crate::metrics::record_agent_llm_split("context_error");
                 tracing::warn!(
                     file_count = files.len(),
                     "LLM error suggests context overflow, splitting batch: {e}"
@@ -466,14 +468,40 @@ pub async fn normalize_batch(
             }
             return Err(e);
         }
-        Err(e) => return Err(e),
+        Err(e) => {
+            crate::metrics::record_agent_llm(
+                llm_model,
+                "error",
+                std::time::Duration::from_millis(duration_ms),
+                0,
+                0,
+                files.len(),
+                Some(estimated),
+            );
+            return Err(e);
+        }
     };
 
     let prompt_tokens = usage.prompt_tokens.unwrap_or(0) as u64;
     let completion_tokens = usage.completion_tokens.unwrap_or(0) as u64;
+    crate::metrics::record_agent_llm(
+        &resp_model,
+        "ok",
+        std::time::Duration::from_millis(duration_ms),
+        prompt_tokens,
+        completion_tokens,
+        files.len(),
+        Some(estimated),
+    );
 
     // Parse batch response
-    let results = parse_batch_response(&response_text, &files)?;
+    let results = match parse_batch_response(&response_text, &files) {
+        Ok(results) => results,
+        Err(error) => {
+            crate::metrics::record_agent_llm_parse_failure(&resp_model);
+            return Err(error);
+        }
+    };
 
     Ok(BatchNormalizeResult {
         results,

src/api/mod.rs

@@ -1,14 +1,27 @@
+use std::marker::PhantomData;
+
+use cot::aide::openapi::{
+    MediaType, Operation, ReferenceOr, RequestBody, Response as OpenApiResponse, SchemaObject,
+    StatusCode as OpenApiStatusCode,
+};
+use cot::auth::PasswordVerificationResult;
+use cot::common_types::Password;
 use cot::db::Database;
+use cot::http::StatusCode;
+use cot::http::header::CONTENT_TYPE;
 use cot::json::Json;
+use cot::openapi::{AsApiOperation, RouteContext};
 use cot::response::IntoResponse;
-use cot::router::method::openapi::api_get;
+use cot::router::method::openapi::{api_get, api_post};
 use cot::router::{Route, Router};
 use cot::session::Session;
-use cot::{App, Body};
-use schemars::JsonSchema;
-use serde::Serialize;
+use cot::{App, Body, RequestHandler};
+use schemars::{JsonSchema, SchemaGenerator};
+use serde::{Deserialize, Serialize};
 
 use crate::auth;
+use crate::config::AppConfig;
+use crate::user::User;
 
 // ---------------------------------------------------------------------------
 // JSON error helper
@@ -23,6 +36,199 @@ fn json_error(status: cot::http::StatusCode, message: &str) -> cot::response::Re
         .expect("valid response")
 }
 
+#[derive(Clone, Copy)]
+struct DocumentedJsonHandler<H, Req, Res> {
+    handler: H,
+    summary: &'static str,
+    _marker: PhantomData<fn(Req) -> Res>,
+}
+
+#[derive(Clone, Copy)]
+struct DocumentedResponseHandler<H, Res> {
+    handler: H,
+    summary: &'static str,
+    _marker: PhantomData<fn() -> Res>,
+}
+
+fn documented_json_handler<Req, Res, H>(
+    handler: H,
+    summary: &'static str,
+) -> DocumentedJsonHandler<H, Req, Res> {
+    DocumentedJsonHandler {
+        handler,
+        summary,
+        _marker: PhantomData,
+    }
+}
+
+fn documented_response_handler<Res, H>(
+    handler: H,
+    summary: &'static str,
+) -> DocumentedResponseHandler<H, Res> {
+    DocumentedResponseHandler {
+        handler,
+        summary,
+        _marker: PhantomData,
+    }
+}
+
+impl<HandlerParams, H, Req, Res> RequestHandler<HandlerParams>
+    for DocumentedJsonHandler<H, Req, Res>
+where
+    H: RequestHandler<HandlerParams> + Clone + Send + Sync + 'static,
+{
+    async fn handle(&self, request: cot::request::Request) -> cot::Result<cot::response::Response> {
+        self.handler.handle(request).await
+    }
+}
+
+impl<HandlerParams, H, Res> RequestHandler<HandlerParams> for DocumentedResponseHandler<H, Res>
+where
+    H: RequestHandler<HandlerParams> + Clone + Send + Sync + 'static,
+{
+    async fn handle(&self, request: cot::request::Request) -> cot::Result<cot::response::Response> {
+        self.handler.handle(request).await
+    }
+}
+
+impl<H, Req, Res> AsApiOperation for DocumentedJsonHandler<H, Req, Res>
+where
+    Req: JsonSchema,
+    Res: JsonSchema,
+{
+    fn as_api_operation(
+        &self,
+        _route_context: &RouteContext<'_>,
+        schema_generator: &mut SchemaGenerator,
+    ) -> Option<Operation> {
+        let mut operation = Operation {
+            summary: Some(self.summary.to_owned()),
+            ..Default::default()
+        };
+
+        let mut request_body = RequestBody {
+            required: true,
+            ..Default::default()
+        };
+        request_body.content.insert(
+            "application/json".to_owned(),
+            MediaType {
+                schema: Some(SchemaObject {
+                    json_schema: Req::json_schema(schema_generator),
+                    external_docs: None,
+                    example: None,
+                }),
+                ..Default::default()
+            },
+        );
+        operation.request_body = Some(ReferenceOr::Item(request_body));
+
+        let responses = operation.responses.get_or_insert_default();
+        let mut ok = OpenApiResponse {
+            description: "OK".to_owned(),
+            ..Default::default()
+        };
+        ok.content.insert(
+            "application/json".to_owned(),
+            MediaType {
+                schema: Some(SchemaObject {
+                    json_schema: Res::json_schema(schema_generator),
+                    external_docs: None,
+                    example: None,
+                }),
+                ..Default::default()
+            },
+        );
+        responses
+            .responses
+            .insert(OpenApiStatusCode::Code(200), ReferenceOr::Item(ok));
+
+        Some(operation)
+    }
+}
+
+impl<H, Res> AsApiOperation for DocumentedResponseHandler<H, Res>
+where
+    Res: JsonSchema,
+{
+    fn as_api_operation(
+        &self,
+        _route_context: &RouteContext<'_>,
+        schema_generator: &mut SchemaGenerator,
+    ) -> Option<Operation> {
+        let mut operation = Operation {
+            summary: Some(self.summary.to_owned()),
+            ..Default::default()
+        };
+        add_json_response::<Res>(&mut operation, schema_generator);
+        Some(operation)
+    }
+}
+
+fn add_json_response<Res: JsonSchema>(
+    operation: &mut Operation,
+    schema_generator: &mut SchemaGenerator,
+) {
+    let responses = operation.responses.get_or_insert_default();
+    let mut ok = OpenApiResponse {
+        description: "OK".to_owned(),
+        ..Default::default()
+    };
+    ok.content.insert(
+        "application/json".to_owned(),
+        MediaType {
+            schema: Some(SchemaObject {
+                json_schema: Res::json_schema(schema_generator),
+                external_docs: None,
+                example: None,
+            }),
+            ..Default::default()
+        },
+    );
+    responses
+        .responses
+        .insert(OpenApiStatusCode::Code(200), ReferenceOr::Item(ok));
+}
+
+fn is_json_content_type(value: &str) -> bool {
+    value
+        .split(';')
+        .next()
+        .map(str::trim)
+        .is_some_and(|media_type| media_type.eq_ignore_ascii_case("application/json"))
+}
+
+async fn parse_json_request<T>(
+    request: cot::request::Request,
+) -> cot::Result<Result<T, cot::response::Response>>
+where
+    T: for<'de> Deserialize<'de>,
+{
+    let content_type = request
+        .headers()
+        .get(CONTENT_TYPE)
+        .and_then(|value| value.to_str().ok())
+        .unwrap_or_default();
+    if !is_json_content_type(content_type) {
+        return Ok(Err(json_error(
+            StatusCode::UNSUPPORTED_MEDIA_TYPE,
+            "expected application/json",
+        )));
+    }
+
+    let bytes = request.into_body().into_bytes().await?;
+    let body = match serde_json::from_slice::<T>(&bytes) {
+        Ok(body) => body,
+        Err(_) => {
+            return Ok(Err(json_error(
+                StatusCode::BAD_REQUEST,
+                "invalid JSON body",
+            )));
+        }
+    };
+    Ok(Ok(body))
+}
+
 // ---------------------------------------------------------------------------
 // GET /api/me
 // ---------------------------------------------------------------------------
@@ -34,8 +240,85 @@ struct MeResponse {
     role: String,
 }
 
-async fn me_handler(session: Session, db: Database) -> cot::Result<cot::response::Response> {
-    let Some(user) = auth::get_session_user(&session, &db).await else {
+#[derive(Debug, Serialize, JsonSchema)]
+struct AuthUserResponse {
+    id: i64,
+    name: String,
+    role: String,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+struct AuthTokenResponse {
+    access_token: String,
+    refresh_token: String,
+    token_type: String,
+    expires_in_seconds: i64,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+struct AuthLoginResponse {
+    user: AuthUserResponse,
+    tokens: AuthTokenResponse,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+struct PasswordLoginRequest {
+    username: String,
+    password: String,
+    device_name: Option<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+struct RefreshRequest {
+    refresh_token: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+struct SsoExchangeRequest {
+    code: String,
+    device_name: Option<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+struct LogoutRequest {
+    refresh_token: Option<String>,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+struct LogoutResponse {
+    revoked: bool,
+}
+
+fn user_response(user: auth::AuthenticatedUser) -> AuthUserResponse {
+    AuthUserResponse {
+        id: user.id,
+        name: user.name,
+        role: user.role.code().to_owned(),
+    }
+}
+
+fn token_response(tokens: auth::ApiTokenPair) -> AuthTokenResponse {
+    AuthTokenResponse {
+        access_token: tokens.access_token,
+        refresh_token: tokens.refresh_token,
+        token_type: tokens.token_type.to_owned(),
+        expires_in_seconds: tokens.expires_in_seconds,
+    }
+}
+
+fn login_response(user: auth::AuthenticatedUser, tokens: auth::ApiTokenPair) -> AuthLoginResponse {
+    AuthLoginResponse {
+        user: user_response(user),
+        tokens: token_response(tokens),
+    }
+}
+
+async fn me_handler(
+    auth_ctx: auth::AuthContext,
+    session: Session,
+    db: Database,
+) -> cot::Result<cot::response::Response> {
+    let Some(user) = auth::get_request_user(&auth_ctx, &session, &db).await else {
         return Ok(json_error(
             cot::http::StatusCode::UNAUTHORIZED,
             "not authenticated",
@@ -50,6 +333,146 @@ async fn me_handler(session: Session, db: Database) -> cot::Result<cot::response
     .into_response()
 }
 
+async fn password_login_handler(
+    db: Database,
+    raw_request: cot::request::Request,
+) -> cot::Result<cot::response::Response> {
+    let request = match parse_json_request::<PasswordLoginRequest>(raw_request).await? {
+        Ok(request) => request,
+        Err(response) => return Ok(response),
+    };
+
+    let (config, _) = AppConfig::load_with_db(&db).await;
+    if !config.auth_password_enabled {
+        crate::metrics::record_auth_attempt("api_password", "failure", "disabled");
+        return Ok(json_error(
+            StatusCode::FORBIDDEN,
+            "password login is disabled",
+        ));
+    }
+
+    let user = match User::get_by_username(&db, request.username.trim()).await {
+        Ok(Some(user)) if user.is_active() => user,
+        _ => {
+            crate::metrics::record_auth_attempt("api_password", "failure", "bad_credentials");
+            return Ok(json_error(
+                StatusCode::UNAUTHORIZED,
+                "invalid username or password",
+            ));
+        }
+    };
+
+    let Some(hash) = user.password_ref() else {
+        crate::metrics::record_auth_attempt("api_password", "failure", "bad_credentials");
+        return Ok(json_error(
+            StatusCode::UNAUTHORIZED,
+            "invalid username or password",
+        ));
+    };
+
+    match hash.verify(&Password::new(&request.password)) {
+        PasswordVerificationResult::Ok | PasswordVerificationResult::OkObsolete(_) => {
+            let auth_user = auth::AuthenticatedUser {
+                id: user.id_val(),
+                name: {
+                    let display = user.display_name_str();
+                    if display.is_empty() {
+                        user.username_str().to_owned()
+                    } else {
+                        display
+                    }
+                },
+                role: user.role(),
+            };
+            let tokens =
+                auth::create_api_session(&db, user.id_val(), request.device_name.as_deref())
+                    .await
+                    .map_err(|e| cot::Error::internal(e.to_string()))?;
+            crate::metrics::record_auth_attempt("api_password", "success", "ok");
+            crate::metrics::record_session_created("api_password");
+            Json(login_response(auth_user, tokens)).into_response()
+        }
+        PasswordVerificationResult::Invalid => {
+            crate::metrics::record_auth_attempt("api_password", "failure", "bad_credentials");
+            Ok(json_error(
+                StatusCode::UNAUTHORIZED,
+                "invalid username or password",
+            ))
+        }
+    }
+}
+
+async fn refresh_handler(
+    db: Database,
+    raw_request: cot::request::Request,
+) -> cot::Result<cot::response::Response> {
+    let request = match parse_json_request::<RefreshRequest>(raw_request).await? {
+        Ok(request) => request,
+        Err(response) => return Ok(response),
+    };
+
+    match auth::refresh_api_session(&db, request.refresh_token.trim()).await {
+        Ok(Some(tokens)) => Json(token_response(tokens)).into_response(),
+        Ok(None) => Ok(json_error(
+            StatusCode::UNAUTHORIZED,
+            "invalid refresh token",
+        )),
+        Err(err) => Err(cot::Error::internal(err.to_string())),
+    }
+}
+
+async fn sso_exchange_handler(
+    db: Database,
+    raw_request: cot::request::Request,
+) -> cot::Result<cot::response::Response> {
+    let request = match parse_json_request::<SsoExchangeRequest>(raw_request).await? {
+        Ok(request) => request,
+        Err(response) => return Ok(response),
+    };
+
+    match auth::exchange_mobile_code_for_api_session(
+        &db,
+        request.code.trim(),
+        request.device_name.as_deref(),
+    )
+    .await
+    {
+        Ok(Some((user, tokens))) => {
+            crate::metrics::record_auth_attempt("api_sso_exchange", "success", "ok");
+            crate::metrics::record_session_created("api_sso_exchange");
+            Json(login_response(user, tokens)).into_response()
+        }
+        Ok(None) => {
+            crate::metrics::record_auth_attempt("api_sso_exchange", "failure", "bad_code");
+            Ok(json_error(
+                StatusCode::UNAUTHORIZED,
+                "invalid SSO exchange code",
+            ))
+        }
+        Err(err) => Err(cot::Error::internal(err.to_string())),
+    }
+}
+
+async fn logout_handler(
+    auth_ctx: auth::AuthContext,
+    db: Database,
+    raw_request: cot::request::Request,
+) -> cot::Result<cot::response::Response> {
+    let request = match parse_json_request::<LogoutRequest>(raw_request).await? {
+        Ok(request) => request,
+        Err(response) => return Ok(response),
+    };
+
+    let revoked = auth::revoke_api_session(
+        &db,
+        auth_ctx.bearer_token(),
+        request.refresh_token.as_deref().map(str::trim),
+    )
+    .await
+    .map_err(|e| cot::Error::internal(e.to_string()))?;
+    Json(LogoutResponse { revoked }).into_response()
+}
+
 // ---------------------------------------------------------------------------
 // App
 // ---------------------------------------------------------------------------
@@ -62,10 +485,101 @@ impl App for ApiApp {
     }
 
     fn router(&self) -> Router {
-        Router::with_urls([Route::with_api_handler_and_name(
-            "/me",
-            api_get(me_handler),
-            "api_me",
-        )])
+        Router::with_urls([
+            Route::with_api_handler_and_name(
+                "/me",
+                api_get(documented_response_handler::<MeResponse, _>(
+                    me_handler,
+                    "Get the current authenticated user",
+                )),
+                "api_me",
+            ),
+            Route::with_api_handler_and_name(
+                "/auth/password",
+                api_post(documented_json_handler::<
+                    PasswordLoginRequest,
+                    AuthLoginResponse,
+                    _,
+                >(
+                    password_login_handler,
+                    "Log in with username and password",
+                )),
+                "api_auth_password",
+            ),
+            Route::with_api_handler_and_name(
+                "/auth/refresh",
+                api_post(documented_json_handler::<
+                    RefreshRequest,
+                    AuthTokenResponse,
+                    _,
+                >(
+                    refresh_handler, "Refresh an API token pair"
+                )),
+                "api_auth_refresh",
+            ),
+            Route::with_api_handler_and_name(
+                "/auth/sso/exchange",
+                api_post(documented_json_handler::<
+                    SsoExchangeRequest,
+                    AuthLoginResponse,
+                    _,
+                >(
+                    sso_exchange_handler,
+                    "Exchange a mobile SSO code for API tokens",
+                )),
+                "api_auth_sso_exchange",
+            ),
+            Route::with_api_handler_and_name(
+                "/auth/logout",
+                api_post(documented_json_handler::<LogoutRequest, LogoutResponse, _>(
+                    logout_handler,
+                    "Revoke an API session",
+                )),
+                "api_auth_logout",
+            ),
+        ])
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use cot::aide::openapi::{PathItem, ReferenceOr};
+
+    use super::*;
+
+    fn assert_get_path(paths: &cot::aide::openapi::Paths, path: &str) {
+        assert!(matches!(
+            paths.paths.get(path),
+            Some(ReferenceOr::Item(PathItem { get: Some(_), .. }))
+        ));
+    }
+
+    fn assert_post_path(paths: &cot::aide::openapi::Paths, path: &str) {
+        assert!(matches!(
+            paths.paths.get(path),
+            Some(ReferenceOr::Item(PathItem { post: Some(_), .. }))
+        ));
+    }
+
+    #[test]
+    fn openapi_includes_auth_routes() {
+        let openapi = ApiApp.router().as_api();
+        let paths = openapi.paths.expect("OpenAPI paths");
+
+        assert_get_path(&paths, "/me");
+        assert_post_path(&paths, "/auth/password");
+        assert_post_path(&paths, "/auth/refresh");
+        assert_post_path(&paths, "/auth/sso/exchange");
+        assert_post_path(&paths, "/auth/logout");
+
+        let Some(ReferenceOr::Item(PathItem {
+            post: Some(operation),
+            ..
+        })) = paths.paths.get("/auth/password")
+        else {
+            panic!("password auth path should be documented as POST");
+        };
+        assert!(operation.request_body.is_some());
+        assert!(operation.responses.is_some());
     }
 }

src/auth.rs

@@ -1,7 +1,13 @@
+use chrono::{Duration, Utc};
 use cot::Body;
-use cot::db::Database;
+use cot::db::{Auto, Database, LimitedString, Model};
+use cot::http::header::AUTHORIZATION;
+use cot::request::RequestHead;
+use cot::request::extractors::FromRequestHead;
 use cot::response::IntoResponse;
 use cot::session::Session;
+use serde::Serialize;
+use sha2::{Digest, Sha256};
 
 use crate::user::User;
 
@@ -37,6 +43,7 @@ impl Role {
 // ---------------------------------------------------------------------------
 
 const SESSION_USER_ID: &str = "user_id";
+const SESSION_POST_LOGIN_REDIRECT: &str = "post_login_redirect";
 
 #[derive(Debug, Clone)]
 pub struct AuthenticatedUser {
@@ -45,11 +52,7 @@ pub struct AuthenticatedUser {
     pub role: Role,
 }
 
-/// Read `user_id` from the session, fetch the `User` from DB, return
-/// `AuthenticatedUser` if the user exists and is active.
-pub async fn get_session_user(session: &Session, db: &Database) -> Option<AuthenticatedUser> {
-    let user_id: i64 = session.get(SESSION_USER_ID).await.ok()??;
-    let user = User::get_by_id(db, user_id).await.ok()??;
+fn authenticated_user_from_user(user: User) -> Option<AuthenticatedUser> {
     if !user.is_active() {
         return None;
     }
@@ -61,6 +64,7 @@ pub async fn get_session_user(session: &Session, db: &Database) -> Option<Authen
             display
         }
     };
+    crate::metrics::record_active_user(user.id_val());
     Some(AuthenticatedUser {
         id: user.id_val(),
         name,
@@ -68,6 +72,362 @@ pub async fn get_session_user(session: &Session, db: &Database) -> Option<Authen
     })
 }
 
+/// Read `user_id` from the session, fetch the `User` from DB, return
+/// `AuthenticatedUser` if the user exists and is active.
+pub async fn get_session_user(session: &Session, db: &Database) -> Option<AuthenticatedUser> {
+    let user_id: i64 = session.get(SESSION_USER_ID).await.ok()??;
+    let user = User::get_by_id(db, user_id).await.ok()??;
+    authenticated_user_from_user(user)
+}
+
+// ---------------------------------------------------------------------------
+// API bearer-token auth
+// ---------------------------------------------------------------------------
+
+const ACCESS_TOKEN_PREFIX: &str = "furu_at_";
+const REFRESH_TOKEN_PREFIX: &str = "furu_rt_";
+const MOBILE_EXCHANGE_CODE_PREFIX: &str = "furu_mx_";
+const ACCESS_TOKEN_TTL_MINUTES: i64 = 15;
+const REFRESH_TOKEN_TTL_DAYS: i64 = 60;
+const MOBILE_EXCHANGE_CODE_TTL_MINUTES: i64 = 3;
+
+#[derive(Debug, Clone, Default)]
+pub struct AuthContext {
+    bearer_token: Option<String>,
+}
+
+impl AuthContext {
+    pub fn bearer_token(&self) -> Option<&str> {
+        self.bearer_token.as_deref()
+    }
+}
+
+impl FromRequestHead for AuthContext {
+    async fn from_request_head(head: &RequestHead) -> cot::Result<Self> {
+        let bearer_token = head
+            .headers
+            .get(AUTHORIZATION)
+            .and_then(|value| value.to_str().ok())
+            .and_then(parse_bearer_token)
+            .map(str::to_owned);
+        Ok(Self { bearer_token })
+    }
+}
+
+fn parse_bearer_token(header: &str) -> Option<&str> {
+    let header = header.trim();
+    let (scheme, token) = header.split_once(' ')?;
+    if !scheme.eq_ignore_ascii_case("Bearer") {
+        return None;
+    }
+    let token = token.trim();
+    if token.is_empty() || token.len() > 512 {
+        return None;
+    }
+    Some(token)
+}
+
+#[derive(Debug, Serialize)]
+pub struct ApiTokenPair {
+    pub access_token: String,
+    pub refresh_token: String,
+    pub token_type: &'static str,
+    pub expires_in_seconds: i64,
+}
+
+#[derive(Debug, Clone)]
+#[cot::db::model]
+pub struct ApiSession {
+    #[model(primary_key)]
+    id: Auto<i64>,
+    user_id: i64,
+    device_name: Option<String>,
+    access_token_hash: LimitedString<128>,
+    refresh_token_hash: LimitedString<128>,
+    access_expires_at: String,
+    refresh_expires_at: String,
+    created_at: String,
+    last_used_at: Option<String>,
+    revoked_at: Option<String>,
+}
+
+#[derive(Debug, Clone)]
+#[cot::db::model]
+pub struct MobileExchangeCode {
+    #[model(primary_key)]
+    id: Auto<i64>,
+    code_hash: LimitedString<128>,
+    user_id: i64,
+    created_at: String,
+    expires_at: String,
+    consumed_at: Option<String>,
+}
+
+impl ApiSession {
+    pub async fn create_for_user(
+        db: &Database,
+        user_id: i64,
+        device_name: Option<&str>,
+    ) -> cot::db::Result<ApiTokenPair> {
+        let tokens = fresh_token_pair();
+        let now = now_iso();
+        let mut session = Self {
+            id: Auto::auto(),
+            user_id,
+            device_name: device_name.and_then(normalize_device_name),
+            access_token_hash: LimitedString::new(&token_hash(&tokens.access_token)).unwrap(),
+            refresh_token_hash: LimitedString::new(&token_hash(&tokens.refresh_token)).unwrap(),
+            access_expires_at: access_expires_at(),
+            refresh_expires_at: refresh_expires_at(),
+            created_at: now.clone(),
+            last_used_at: Some(now),
+            revoked_at: None,
+        };
+        session.insert(db).await?;
+        Ok(tokens)
+    }
+
+    async fn find_by_access_token(db: &Database, token: &str) -> cot::db::Result<Option<Self>> {
+        let Ok(hash) = LimitedString::<128>::new(&token_hash(token)) else {
+            return Ok(None);
+        };
+        cot::db::query!(ApiSession, $access_token_hash == hash)
+            .get(db)
+            .await
+    }
+
+    async fn find_by_refresh_token(db: &Database, token: &str) -> cot::db::Result<Option<Self>> {
+        let Ok(hash) = LimitedString::<128>::new(&token_hash(token)) else {
+            return Ok(None);
+        };
+        cot::db::query!(ApiSession, $refresh_token_hash == hash)
+            .get(db)
+            .await
+    }
+
+    fn is_revoked(&self) -> bool {
+        self.revoked_at.is_some()
+    }
+
+    fn access_token_valid(&self) -> bool {
+        !self.is_revoked() && self.access_expires_at > now_iso()
+    }
+
+    fn refresh_token_valid(&self) -> bool {
+        !self.is_revoked() && self.refresh_expires_at > now_iso()
+    }
+
+    async fn rotate(&mut self, db: &Database) -> cot::db::Result<ApiTokenPair> {
+        let tokens = fresh_token_pair();
+        self.access_token_hash = LimitedString::new(&token_hash(&tokens.access_token)).unwrap();
+        self.refresh_token_hash = LimitedString::new(&token_hash(&tokens.refresh_token)).unwrap();
+        self.access_expires_at = access_expires_at();
+        self.refresh_expires_at = refresh_expires_at();
+        self.last_used_at = Some(now_iso());
+        self.save(db).await?;
+        Ok(tokens)
+    }
+
+    async fn revoke(&mut self, db: &Database) -> cot::db::Result<()> {
+        if self.revoked_at.is_none() {
+            self.revoked_at = Some(now_iso());
+            self.save(db).await?;
+        }
+        Ok(())
+    }
+}
+
+pub async fn create_api_session(
+    db: &Database,
+    user_id: i64,
+    device_name: Option<&str>,
+) -> cot::db::Result<ApiTokenPair> {
+    ApiSession::create_for_user(db, user_id, device_name).await
+}
+
+pub async fn get_bearer_user(db: &Database, token: &str) -> Option<AuthenticatedUser> {
+    let session = ApiSession::find_by_access_token(db, token).await.ok()??;
+    if !session.access_token_valid() {
+        return None;
+    }
+    let user = User::get_by_id(db, session.user_id).await.ok()??;
+    authenticated_user_from_user(user)
+}
+
+pub async fn get_request_user(
+    auth: &AuthContext,
+    session: &Session,
+    db: &Database,
+) -> Option<AuthenticatedUser> {
+    if let Some(token) = auth.bearer_token() {
+        return get_bearer_user(db, token).await;
+    }
+    get_session_user(session, db).await
+}
+
+pub async fn refresh_api_session(
+    db: &Database,
+    refresh_token: &str,
+) -> cot::db::Result<Option<ApiTokenPair>> {
+    let Some(mut session) = ApiSession::find_by_refresh_token(db, refresh_token).await? else {
+        return Ok(None);
+    };
+    if !session.refresh_token_valid() {
+        session.revoke(db).await?;
+        return Ok(None);
+    }
+    let Some(user) = User::get_by_id(db, session.user_id).await? else {
+        session.revoke(db).await?;
+        return Ok(None);
+    };
+    if !user.is_active() {
+        session.revoke(db).await?;
+        return Ok(None);
+    }
+    Ok(Some(session.rotate(db).await?))
+}
+
+pub async fn revoke_api_session(
+    db: &Database,
+    access_token: Option<&str>,
+    refresh_token: Option<&str>,
+) -> cot::db::Result<bool> {
+    let mut session = if let Some(token) = access_token {
+        ApiSession::find_by_access_token(db, token).await?
+    } else {
+        None
+    };
+    if session.is_none() {
+        if let Some(token) = refresh_token {
+            session = ApiSession::find_by_refresh_token(db, token).await?;
+        }
+    }
+    let Some(mut session) = session else {
+        return Ok(false);
+    };
+    session.revoke(db).await?;
+    Ok(true)
+}
+
+impl MobileExchangeCode {
+    pub async fn create_for_user(db: &Database, user_id: i64) -> cot::db::Result<String> {
+        let code = random_token(MOBILE_EXCHANGE_CODE_PREFIX);
+        let now = now_iso();
+        let mut row = Self {
+            id: Auto::auto(),
+            code_hash: LimitedString::new(&token_hash(&code)).unwrap(),
+            user_id,
+            created_at: now,
+            expires_at: mobile_exchange_code_expires_at(),
+            consumed_at: None,
+        };
+        row.insert(db).await?;
+        Ok(code)
+    }
+
+    async fn find_by_code(db: &Database, code: &str) -> cot::db::Result<Option<Self>> {
+        let Ok(hash) = LimitedString::<128>::new(&token_hash(code)) else {
+            return Ok(None);
+        };
+        cot::db::query!(MobileExchangeCode, $code_hash == hash)
+            .get(db)
+            .await
+    }
+
+    fn is_valid(&self) -> bool {
+        self.consumed_at.is_none() && self.expires_at > now_iso()
+    }
+
+    async fn consume(&mut self, db: &Database) -> cot::db::Result<()> {
+        self.consumed_at = Some(now_iso());
+        self.save(db).await
+    }
+}
+
+pub async fn create_mobile_exchange_code(db: &Database, user_id: i64) -> cot::db::Result<String> {
+    MobileExchangeCode::create_for_user(db, user_id).await
+}
+
+pub async fn exchange_mobile_code_for_api_session(
+    db: &Database,
+    code: &str,
+    device_name: Option<&str>,
+) -> cot::db::Result<Option<(AuthenticatedUser, ApiTokenPair)>> {
+    let Some(mut exchange_code) = MobileExchangeCode::find_by_code(db, code).await? else {
+        return Ok(None);
+    };
+    if !exchange_code.is_valid() {
+        return Ok(None);
+    }
+    let Some(user) = User::get_by_id(db, exchange_code.user_id).await? else {
+        exchange_code.consume(db).await?;
+        return Ok(None);
+    };
+    let Some(auth_user) = authenticated_user_from_user(user) else {
+        exchange_code.consume(db).await?;
+        return Ok(None);
+    };
+    exchange_code.consume(db).await?;
+    let tokens = ApiSession::create_for_user(db, auth_user.id, device_name).await?;
+    Ok(Some((auth_user, tokens)))
+}
+
+fn fresh_token_pair() -> ApiTokenPair {
+    ApiTokenPair {
+        access_token: random_token(ACCESS_TOKEN_PREFIX),
+        refresh_token: random_token(REFRESH_TOKEN_PREFIX),
+        token_type: "Bearer",
+        expires_in_seconds: ACCESS_TOKEN_TTL_MINUTES * 60,
+    }
+}
+
+fn random_token(prefix: &str) -> String {
+    format!(
+        "{prefix}{}{}",
+        uuid::Uuid::new_v4().simple(),
+        uuid::Uuid::new_v4().simple()
+    )
+}
+
+fn token_hash(token: &str) -> String {
+    let digest = Sha256::digest(token.as_bytes());
+    let mut out = String::with_capacity(digest.len() * 2);
+    for byte in digest {
+        out.push_str(&format!("{byte:02x}"));
+    }
+    out
+}
+
+fn normalize_device_name(name: &str) -> Option<String> {
+    let trimmed = name.trim();
+    if trimmed.is_empty() {
+        return None;
+    }
+    Some(trimmed.chars().take(255).collect())
+}
+
+fn now_iso() -> String {
+    Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string()
+}
+
+fn access_expires_at() -> String {
+    (Utc::now() + Duration::minutes(ACCESS_TOKEN_TTL_MINUTES))
+        .format("%Y-%m-%dT%H:%M:%SZ")
+        .to_string()
+}
+
+fn refresh_expires_at() -> String {
+    (Utc::now() + Duration::days(REFRESH_TOKEN_TTL_DAYS))
+        .format("%Y-%m-%dT%H:%M:%SZ")
+        .to_string()
+}
+
+fn mobile_exchange_code_expires_at() -> String {
+    (Utc::now() + Duration::minutes(MOBILE_EXCHANGE_CODE_TTL_MINUTES))
+        .format("%Y-%m-%dT%H:%M:%SZ")
+        .to_string()
+}
+
 /// Return `Ok(user)` if the session belongs to an active admin, otherwise
 /// `Err(response)` — a redirect to `/login` or a 403.
 pub async fn require_admin_or_redirect(
@@ -75,9 +435,11 @@ pub async fn require_admin_or_redirect(
     db: &Database,
 ) -> Result<AuthenticatedUser, cot::response::Response> {
     let Some(user) = get_session_user(session, db).await else {
+        crate::metrics::record_authorization_denied("unauthenticated");
         return Err(redirect("/login"));
     };
     if user.role != Role::Admin {
+        crate::metrics::record_authorization_denied("forbidden");
         return Err("Forbidden"
             .with_status(cot::http::StatusCode::FORBIDDEN)
             .into_response()
@@ -96,9 +458,47 @@ pub async fn login(session: &Session, user_id: i64) -> cot::Result<()> {
         .insert(SESSION_USER_ID, user_id)
         .await
         .map_err(|e| cot::Error::internal(e.to_string()))?;
+    crate::metrics::record_active_user(user_id);
     Ok(())
 }
 
+pub async fn remember_post_login_redirect(session: &Session, location: &str) -> cot::Result<()> {
+    if let Some(location) = safe_internal_redirect(location) {
+        session
+            .insert(SESSION_POST_LOGIN_REDIRECT, location)
+            .await
+            .map_err(|e| cot::Error::internal(e.to_string()))?;
+    }
+    Ok(())
+}
+
+pub async fn get_post_login_redirect(session: &Session) -> cot::Result<Option<String>> {
+    let location: Option<String> = session
+        .get(SESSION_POST_LOGIN_REDIRECT)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    Ok(location.and_then(|value| safe_internal_redirect(&value)))
+}
+
+pub async fn clear_post_login_redirect(session: &Session) -> cot::Result<()> {
+    let _: Option<String> = session
+        .remove(SESSION_POST_LOGIN_REDIRECT)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    Ok(())
+}
+
+fn safe_internal_redirect(location: &str) -> Option<String> {
+    let location = location.trim();
+    if !location.starts_with('/') || location.starts_with("//") {
+        return None;
+    }
+    if location.bytes().any(|b| matches!(b, b'\r' | b'\n')) {
+        return None;
+    }
+    Some(location.chars().take(2048).collect())
+}
+
 /// Flush (destroy) the session.
 pub async fn logout(session: &Session) -> cot::Result<()> {
     session
@@ -117,6 +517,192 @@ pub fn redirect(location: &str) -> cot::response::Response {
         .expect("valid response")
 }
 
+// ---------------------------------------------------------------------------
+// Migrations
+// ---------------------------------------------------------------------------
+
+pub mod db_migrations {
+    use cot::db::migrations::{self, Field, Operation, SyncDynMigration};
+    use cot::db::{DatabaseField, Identifier, LimitedString};
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0038CreateApiSession;
+
+    impl migrations::Migration for M0038CreateApiSession {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0038_create_api_session";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0003_create_user",
+            )];
+        const OPERATIONS: &'static [Operation] = &[Operation::create_model()
+            .table_name(Identifier::new("furumusic__api_session"))
+            .fields(&[
+                Field::new(Identifier::new("id"), <i64 as DatabaseField>::TYPE)
+                    .primary_key()
+                    .auto(),
+                Field::new(Identifier::new("user_id"), <i64 as DatabaseField>::TYPE),
+                Field::new(
+                    Identifier::new("device_name"),
+                    <String as DatabaseField>::TYPE,
+                )
+                .set_null(true),
+                Field::new(
+                    Identifier::new("access_token_hash"),
+                    <LimitedString<128> as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("refresh_token_hash"),
+                    <LimitedString<128> as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("access_expires_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("refresh_expires_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("created_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("last_used_at"),
+                    <String as DatabaseField>::TYPE,
+                )
+                .set_null(true),
+                Field::new(
+                    Identifier::new("revoked_at"),
+                    <String as DatabaseField>::TYPE,
+                )
+                .set_null(true),
+            ])
+            .build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_api_session_indexes(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX idx_api_session_access_token_hash \
+                     ON furumusic__api_session (access_token_hash)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX idx_api_session_refresh_token_hash \
+                     ON furumusic__api_session (refresh_token_hash)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX idx_api_session_user_id \
+                     ON furumusic__api_session (user_id)",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0039CreateApiSessionIndexes;
+
+    impl migrations::Migration for M0039CreateApiSessionIndexes {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0039_create_api_session_indexes";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0038_create_api_session",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_api_session_indexes).build()];
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0040CreateMobileExchangeCode;
+
+    impl migrations::Migration for M0040CreateMobileExchangeCode {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0040_create_mobile_exchange_code";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0039_create_api_session_indexes",
+            )];
+        const OPERATIONS: &'static [Operation] = &[Operation::create_model()
+            .table_name(Identifier::new("furumusic__mobile_exchange_code"))
+            .fields(&[
+                Field::new(Identifier::new("id"), <i64 as DatabaseField>::TYPE)
+                    .primary_key()
+                    .auto(),
+                Field::new(
+                    Identifier::new("code_hash"),
+                    <LimitedString<128> as DatabaseField>::TYPE,
+                ),
+                Field::new(Identifier::new("user_id"), <i64 as DatabaseField>::TYPE),
+                Field::new(
+                    Identifier::new("created_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("expires_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("consumed_at"),
+                    <String as DatabaseField>::TYPE,
+                )
+                .set_null(true),
+            ])
+            .build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_mobile_exchange_code_indexes(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX idx_mobile_exchange_code_hash \
+                     ON furumusic__mobile_exchange_code (code_hash)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX idx_mobile_exchange_code_user_id \
+                     ON furumusic__mobile_exchange_code (user_id)",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0041CreateMobileExchangeCodeIndexes;
+
+    impl migrations::Migration for M0041CreateMobileExchangeCodeIndexes {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0041_create_mobile_exchange_code_indexes";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0040_create_mobile_exchange_code",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_mobile_exchange_code_indexes).build()];
+    }
+
+    pub const MIGRATIONS: &[&SyncDynMigration] = &[
+        &M0038CreateApiSession,
+        &M0039CreateApiSessionIndexes,
+        &M0040CreateMobileExchangeCode,
+        &M0041CreateMobileExchangeCodeIndexes,
+    ];
+}
+
 // ---------------------------------------------------------------------------
 // Tests
 // ---------------------------------------------------------------------------

src/config.rs

@@ -135,6 +135,9 @@ pub struct ConfigSources {
     pub agent_concurrency: ConfigSource,
     pub lastfm_api_key: ConfigSource,
     pub lastfm_shared_secret: ConfigSource,
+    pub federation_enabled: ConfigSource,
+    pub federation_network_id: ConfigSource,
+    pub federation_save_on_listen: ConfigSource,
 }
 
 impl Default for ConfigSources {
@@ -162,6 +165,9 @@ impl Default for ConfigSources {
             agent_concurrency: ConfigSource::Default,
             lastfm_api_key: ConfigSource::Default,
             lastfm_shared_secret: ConfigSource::Default,
+            federation_enabled: ConfigSource::Default,
+            federation_network_id: ConfigSource::Default,
+            federation_save_on_listen: ConfigSource::Default,
         }
     }
 }
@@ -270,6 +276,15 @@ pub struct AppConfig {
     pub lastfm_api_key: String,
     /// Last.fm shared secret for authenticated scrobbling calls.
     pub lastfm_shared_secret: String,
+    /// Whether this server participates in the furumi federation (publishes
+    /// its library into the shared DHT and serves audio to peers).
+    pub federation_enabled: bool,
+    /// Federation network id — the shared secret every peer of the network
+    /// uses to find the others.
+    pub federation_network_id: String,
+    /// Whether a federated track requested for playback is imported into the
+    /// shared local library. This is a server-wide administrator policy.
+    pub federation_save_on_listen: bool,
 }
 
 impl Default for AppConfig {
@@ -297,6 +312,9 @@ impl Default for AppConfig {
             agent_concurrency: 2,
             lastfm_api_key: String::new(),
             lastfm_shared_secret: String::new(),
+            federation_enabled: false,
+            federation_network_id: String::new(),
+            federation_save_on_listen: false,
         }
     }
 }
@@ -325,6 +343,9 @@ impl_env_overrides!(
     agent_concurrency,
     lastfm_api_key,
     lastfm_shared_secret,
+    federation_enabled,
+    federation_network_id,
+    federation_save_on_listen,
 );
 
 impl AppConfig {
@@ -338,10 +359,52 @@ impl AppConfig {
     pub fn load() -> Self {
         let mut cfg = Self::default();
         cfg.apply_env_overrides();
+        cfg.apply_startup_db_overrides();
+        cfg.apply_env_overrides();
         cfg.normalize_host_paths();
         cfg
     }
 
+    fn apply_startup_db_overrides(&mut self) {
+        if self.database_url.is_empty() {
+            return;
+        }
+        if tokio::runtime::Handle::try_current().is_ok() {
+            tracing::warn!("skipping startup DB config load from inside an existing Tokio runtime");
+            return;
+        }
+
+        let database_url = self.database_url.clone();
+        let Ok(runtime) = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+        else {
+            tracing::warn!("failed to create runtime for startup DB config load");
+            return;
+        };
+
+        let result = runtime.block_on(async move {
+            let pool = sqlx::postgres::PgPoolOptions::new()
+                .max_connections(1)
+                .connect(&database_url)
+                .await?;
+            sqlx::query_scalar::<_, String>(
+                "SELECT value FROM furumusic__config_entry WHERE key = 'swagger_enabled'",
+            )
+            .fetch_optional(&pool)
+            .await
+        });
+
+        match result {
+            Ok(Some(value)) => match value.parse::<bool>() {
+                Ok(value) => self.swagger_enabled = value,
+                Err(_) => tracing::warn!("ignoring invalid DB config value for swagger_enabled"),
+            },
+            Ok(None) => {}
+            Err(err) => tracing::warn!("failed to read startup DB config overrides: {err}"),
+        }
+    }
+
     /// Build config with full 3-layer resolution (default → DB → env) and
     /// track the source of each field.
     pub async fn load_with_db(db: &Database) -> (Self, ConfigSources) {
@@ -410,6 +473,9 @@ impl AppConfig {
         apply_db_field!(agent_concurrency);
         apply_db_field!(lastfm_api_key);
         apply_db_field!(lastfm_shared_secret);
+        apply_db_field!(federation_enabled);
+        apply_db_field!(federation_network_id);
+        apply_db_field!(federation_save_on_listen);
     }
 }
 

src/federation/client.rs

@@ -0,0 +1,536 @@
+//! Receiving side of music federation.
+//!
+//! User-facing identity is content-addressed. An `(owner, item_id)` pair is
+//! only a source locator and several locators may resolve the same track.
+
+use std::collections::HashMap;
+
+use anyhow::{Context, Result};
+use music_dht::{ItemKind, LibraryItem, normalize_content_id};
+use serde::Serialize;
+use serde_json::{Value, json};
+use sqlx::Row as _;
+use tokio::io::AsyncReadExt;
+
+use super::{Federation, now_iso};
+
+const MAX_CATALOG_BYTES: u64 = 4 * 1024 * 1024;
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TrackKeyDto {
+    pub content_id: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ArtistKeyDto {
+    pub normalized_name: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ArtistRefDto {
+    pub key: ArtistKeyDto,
+    pub name: String,
+    pub local_id: Option<i64>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ReleaseKeyDto {
+    pub normalized_title: String,
+    pub primary_artists: Vec<String>,
+    pub release_type: Option<String>,
+    pub year: Option<i32>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ReleaseRefDto {
+    pub key: ReleaseKeyDto,
+    pub local_id: Option<i64>,
+    pub title: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct FederationSourceDto {
+    pub owner: String,
+    pub item_id: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct LocalAvailabilityDto {
+    pub track_id: i64,
+    pub stream_url: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TrackMetadataDto {
+    pub title: String,
+    pub artists: Vec<ArtistRefDto>,
+    pub featured_artists: Vec<ArtistRefDto>,
+    pub release: Option<ReleaseRefDto>,
+    pub year: Option<i32>,
+    pub duration_seconds: Option<f64>,
+    pub track_number: Option<i32>,
+    pub disc_number: Option<i32>,
+    pub cover_url: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TrackAvailabilityDto {
+    pub state: &'static str,
+    pub local: Option<LocalAvailabilityDto>,
+    pub federation: Vec<FederationSourceDto>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TrackDto {
+    pub key: TrackKeyDto,
+    pub metadata: TrackMetadataDto,
+    pub availability: TrackAvailabilityDto,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct SearchEvent {
+    pub search_id: String,
+    pub sequence: u64,
+    pub kind: &'static str,
+    pub peer: Option<String>,
+    pub entity_key: Value,
+    pub entity: Value,
+}
+
+impl Federation {
+    pub fn stream_artist_catalogs(
+        self: &std::sync::Arc<Self>,
+        name: String,
+    ) -> tokio::sync::mpsc::UnboundedReceiver<Result<(String, music_dht::catalog::CatalogArtist)>>
+    {
+        let (sender, receiver) = tokio::sync::mpsc::unbounded_channel();
+        let federation = std::sync::Arc::clone(self);
+        tokio::spawn(async move {
+            let result = async {
+                let service = federation.service().await?;
+                let normalized = music_dht::normalize_name(&name);
+                let outcome = service
+                    .search_network(&name)
+                    .await
+                    .map_err(|err| anyhow::anyhow!("federated artist search failed: {err}"))?;
+                let owners: std::collections::HashSet<_> = outcome
+                    .network_results
+                    .iter()
+                    .filter(|item| {
+                        (item.kind == ItemKind::Artist && item.normalized_name == normalized)
+                            || item
+                                .artist_names
+                                .iter()
+                                .chain(&item.featured_artist_names)
+                                .any(|artist| music_dht::normalize_name(artist) == normalized)
+                    })
+                    .map(|item| item.owner)
+                    .collect();
+                for owner in owners {
+                    let service = std::sync::Arc::clone(&service);
+                    let sender = sender.clone();
+                    let name = name.clone();
+                    tokio::spawn(async move {
+                        let result = tokio::time::timeout(
+                            std::time::Duration::from_secs(8),
+                            fetch_artist_catalog(&service, owner, &name),
+                        )
+                        .await
+                        .map_err(|_| anyhow::anyhow!("catalog request timed out"))
+                        .and_then(|result| result)
+                        .map(|artist| (owner.to_string(), artist));
+                        let _ = sender.send(result);
+                    });
+                }
+                Ok::<(), anyhow::Error>(())
+            }
+            .await;
+            if let Err(err) = result {
+                let _ = sender.send(Err(err));
+            }
+        });
+        receiver
+    }
+
+    /// Performs one bounded DHT search and returns entity upserts. The HTTP
+    /// layer streams each upsert independently; catalog fan-out can append
+    /// events to the same contract without changing the browser model.
+    pub async fn search_events(&self, search_id: &str, query: &str) -> Result<Vec<SearchEvent>> {
+        let query = query.trim();
+        anyhow::ensure!(!query.is_empty(), "search query is empty");
+        anyhow::ensure!(query.chars().count() <= 200, "search query is too long");
+
+        let started = std::time::Instant::now();
+        let service = self.service().await?;
+        tracing::info!(
+            search_id,
+            query,
+            connected_peers = service.connected_peers().len(),
+            known_contacts = service.known_peers().len(),
+            "federated search started"
+        );
+        let own = service.endpoint_id();
+        let result = tokio::time::timeout(
+            std::time::Duration::from_secs(20),
+            service.search_network(query),
+        )
+        .await
+        .map_err(|_| anyhow::anyhow!("federated search timed out after 20 seconds"))?
+        .map_err(|err| anyhow::anyhow!("federated search failed: {err}"))?;
+        tracing::info!(
+            search_id,
+            query,
+            local_results = result.local_results.len(),
+            network_results = result.network_results.len(),
+            queried_nodes = result.queried_nodes,
+            elapsed_ms = started.elapsed().as_millis() as u64,
+            "federated DHT search finished"
+        );
+        let all_items: Vec<LibraryItem> = result
+            .local_results
+            .into_iter()
+            .chain(result.network_results)
+            .collect();
+
+        let pool = self.pool().await?;
+        let mut by_content: HashMap<String, TrackDto> = HashMap::new();
+        for item in all_items.iter().filter(|item| item.kind == ItemKind::Track) {
+            let Some(content_id) = item.content_id.as_deref().and_then(normalize_content_id) else {
+                // A globally usable track reference must be verifiable.
+                continue;
+            };
+            let local = local_availability(&pool, &content_id).await?;
+            let source = FederationSourceDto {
+                owner: item.owner.to_string(),
+                item_id: hex(item.id.as_bytes()),
+            };
+            let entry = by_content.entry(content_id.clone()).or_insert_with(|| {
+                track_from_item(content_id.clone(), item, local, item.owner == own)
+            });
+            if !entry.availability.federation.iter().any(|candidate| {
+                candidate.owner == source.owner && candidate.item_id == source.item_id
+            }) {
+                entry.availability.federation.push(source);
+            }
+            if entry.availability.local.is_some() {
+                entry.availability.state = "local";
+            }
+        }
+
+        let mut tracks: Vec<_> = by_content.into_values().collect();
+        tracks.sort_by(|left, right| {
+            left.metadata
+                .title
+                .to_lowercase()
+                .cmp(&right.metadata.title.to_lowercase())
+        });
+
+        let mut events = Vec::with_capacity(all_items.len());
+        for (index, track) in tracks.into_iter().enumerate() {
+            persist_track_ref(&pool, &track).await?;
+            let peer = track
+                .availability
+                .federation
+                .first()
+                .map(|source| source.owner.clone());
+            events.push(SearchEvent {
+                search_id: search_id.to_owned(),
+                sequence: index as u64 + 1,
+                kind: "federation.track",
+                peer,
+                entity_key: serde_json::to_value(&track.key)?,
+                entity: serde_json::to_value(track)?,
+            });
+        }
+        let mut artist_peers: HashMap<String, (String, Vec<String>)> = HashMap::new();
+        let mut releases: HashMap<String, Value> = HashMap::new();
+        for item in &all_items {
+            match item.kind {
+                ItemKind::Artist => {
+                    let key = music_dht::normalize_name(&item.name);
+                    let entry = artist_peers
+                        .entry(key)
+                        .or_insert_with(|| (item.name.clone(), Vec::new()));
+                    let owner = item.owner.to_string();
+                    if !entry.1.contains(&owner) {
+                        entry.1.push(owner);
+                    }
+                }
+                ItemKind::Release => {
+                    let artist_keys: Vec<String> = item
+                        .artist_names
+                        .iter()
+                        .map(|name| music_dht::normalize_name(name))
+                        .collect();
+                    let normalized_title = music_dht::normalize_name(&item.name);
+                    let cover_url = all_items
+                        .iter()
+                        .find(|track| {
+                            track.kind == ItemKind::Track
+                                && track.release_title.as_deref().is_some_and(|title| {
+                                    music_dht::normalize_name(title) == normalized_title
+                                })
+                                && track.year == item.year
+                        })
+                        .map(|track| {
+                            format!(
+                                "/api/player/federation/tracks/artwork?owner={}&item_id={}",
+                                track.owner,
+                                hex(track.id.as_bytes())
+                            )
+                        });
+                    let key = format!(
+                        "{}|{}|{}",
+                        normalized_title,
+                        artist_keys.join(","),
+                        item.year.map_or_else(String::new, |year| year.to_string())
+                    );
+                    releases.entry(key.clone()).or_insert_with(|| {
+                        json!({
+                            "key": {
+                                "normalized_title": music_dht::normalize_name(&item.name),
+                                "primary_artists": artist_keys,
+                                "release_type": null,
+                                "year": item.year,
+                            },
+                            "title": item.name,
+                            "artists": item.artist_names,
+                            "year": item.year,
+                            "cover_url": cover_url,
+                            "sources": [{
+                                "owner": item.owner.to_string(),
+                                "item_id": hex(item.id.as_bytes()),
+                            }],
+                        })
+                    });
+                }
+                ItemKind::Track => {}
+            }
+        }
+        for (key, (name, peers)) in artist_peers {
+            let sequence = events.len() as u64 + 1;
+            events.push(SearchEvent {
+                search_id: search_id.to_owned(),
+                sequence,
+                kind: "federation.artist",
+                peer: peers.first().cloned(),
+                entity_key: json!({ "normalized_name": key }),
+                entity: json!({
+                    "key": { "normalized_name": key },
+                    "name": name,
+                    "image_url": null,
+                    "peers": peers,
+                }),
+            });
+        }
+        for (key, release) in releases {
+            let sequence = events.len() as u64 + 1;
+            events.push(SearchEvent {
+                search_id: search_id.to_owned(),
+                sequence,
+                kind: "federation.release",
+                peer: None,
+                entity_key: json!({ "composite": key }),
+                entity: release,
+            });
+        }
+        tracing::info!(
+            search_id,
+            query,
+            events = events.len(),
+            elapsed_ms = started.elapsed().as_millis() as u64,
+            "federated search response ready"
+        );
+        Ok(events)
+    }
+}
+
+async fn fetch_artist_catalog(
+    service: &music_dht::MusicDhtService,
+    owner: music_dht::EndpointId,
+    artist: &str,
+) -> Result<music_dht::catalog::CatalogArtist> {
+    let mut stream = service
+        .open_stream(owner, super::CATALOG_ALPN)
+        .await
+        .map_err(|err| anyhow::anyhow!("cannot reach catalog peer: {err}"))?;
+    let mut request = serde_json::to_vec(&music_dht::catalog::CatalogRequest {
+        artist: artist.to_owned(),
+        want: Some("catalog".to_owned()),
+        ..Default::default()
+    })?;
+    request.push(b'\n');
+    stream.send.write_all(&request).await?;
+    stream.send.finish()?;
+    let mut payload = Vec::new();
+    stream
+        .recv
+        .take(MAX_CATALOG_BYTES + 1)
+        .read_to_end(&mut payload)
+        .await?;
+    anyhow::ensure!(
+        payload.len() as u64 <= MAX_CATALOG_BYTES,
+        "catalog response is too large"
+    );
+    let response: music_dht::catalog::CatalogResponse =
+        serde_json::from_slice(&payload).context("invalid catalog response")?;
+    anyhow::ensure!(
+        response.ok,
+        "peer refused catalog: {}",
+        response.error.unwrap_or_else(|| "unknown error".to_owned())
+    );
+    response.artist.context("peer returned no artist catalog")
+}
+
+fn track_from_item(
+    content_id: String,
+    item: &LibraryItem,
+    local: Option<LocalAvailabilityDto>,
+    own: bool,
+) -> TrackDto {
+    let owner = item.owner.to_string();
+    let item_id = hex(item.id.as_bytes());
+    let artists = artist_refs(&item.artist_names);
+    let featured_artists = artist_refs(&item.featured_artist_names);
+    let release = item.release_title.as_ref().map(|title| ReleaseRefDto {
+        key: ReleaseKeyDto {
+            normalized_title: music_dht::normalize_name(title),
+            primary_artists: item
+                .artist_names
+                .iter()
+                .map(|artist| music_dht::normalize_name(artist))
+                .collect(),
+            release_type: None,
+            year: item.year,
+        },
+        local_id: None,
+        title: title.clone(),
+    });
+    let state = if local.is_some() || own {
+        "local"
+    } else {
+        "federated"
+    };
+    TrackDto {
+        key: TrackKeyDto { content_id },
+        metadata: TrackMetadataDto {
+            title: item.name.clone(),
+            artists,
+            featured_artists,
+            release,
+            year: item.year,
+            duration_seconds: item.duration_seconds,
+            track_number: item.track_number,
+            disc_number: item.disc_number,
+            cover_url: Some(format!(
+                "/api/player/federation/tracks/artwork?owner={owner}&item_id={item_id}"
+            )),
+        },
+        availability: TrackAvailabilityDto {
+            state,
+            local,
+            federation: vec![FederationSourceDto { owner, item_id }],
+        },
+    }
+}
+
+fn artist_refs(names: &[String]) -> Vec<ArtistRefDto> {
+    names
+        .iter()
+        .map(|name| ArtistRefDto {
+            key: ArtistKeyDto {
+                normalized_name: music_dht::normalize_name(name),
+            },
+            name: name.clone(),
+            local_id: None,
+        })
+        .collect()
+}
+
+async fn local_availability(
+    pool: &sqlx::PgPool,
+    content_id: &str,
+) -> Result<Option<LocalAvailabilityDto>> {
+    let row = sqlx::query(
+        "SELECT t.id
+           FROM furumusic__federation_content_id_cache c
+           JOIN furumusic__track t ON t.audio_file_id = c.media_file_id
+          WHERE c.content_id = $1 AND t.is_hidden = false
+          LIMIT 1",
+    )
+    .bind(content_id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| {
+        let track_id: i64 = row.get(0);
+        LocalAvailabilityDto {
+            track_id,
+            stream_url: format!("/api/player/stream/{track_id}"),
+        }
+    }))
+}
+
+async fn persist_track_ref(pool: &sqlx::PgPool, track: &TrackDto) -> Result<()> {
+    let metadata = serde_json::to_value(&track.metadata)?;
+    let local_id = track
+        .availability
+        .local
+        .as_ref()
+        .map(|local| local.track_id);
+    let row = sqlx::query(
+        "INSERT INTO furumusic__track_ref
+            (content_id, local_track_id, title, release_title, year,
+             duration_seconds, metadata_json, metadata_authority, created_at, updated_at)
+         VALUES ($1, $2, $3, $4, $5, $6, $7, 'federation', $8, $8)
+         ON CONFLICT (content_id) DO UPDATE SET
+            local_track_id = COALESCE(furumusic__track_ref.local_track_id, EXCLUDED.local_track_id),
+            title = EXCLUDED.title,
+            release_title = EXCLUDED.release_title,
+            year = EXCLUDED.year,
+            duration_seconds = EXCLUDED.duration_seconds,
+            metadata_json = EXCLUDED.metadata_json,
+            updated_at = EXCLUDED.updated_at
+         RETURNING id",
+    )
+    .bind(&track.key.content_id)
+    .bind(local_id)
+    .bind(&track.metadata.title)
+    .bind(
+        track
+            .metadata
+            .release
+            .as_ref()
+            .map(|release| &release.title),
+    )
+    .bind(track.metadata.year)
+    .bind(track.metadata.duration_seconds)
+    .bind(metadata)
+    .bind(now_iso())
+    .fetch_one(pool)
+    .await
+    .context("persisting content-addressed track reference failed")?;
+    let track_ref_id: i64 = row.get(0);
+    for source in &track.availability.federation {
+        sqlx::query(
+            "INSERT INTO furumusic__federation_track_source
+                (track_ref_id, owner_peer_id, item_id, last_seen_ms, metadata_json)
+             VALUES ($1, $2, $3, $4, $5)
+             ON CONFLICT (owner_peer_id, item_id) DO UPDATE SET
+                track_ref_id = EXCLUDED.track_ref_id,
+                last_seen_ms = EXCLUDED.last_seen_ms,
+                metadata_json = EXCLUDED.metadata_json",
+        )
+        .bind(track_ref_id)
+        .bind(&source.owner)
+        .bind(&source.item_id)
+        .bind(chrono::Utc::now().timestamp_millis())
+        .bind(json!({ "track": track.metadata }))
+        .execute(pool)
+        .await?;
+    }
+    Ok(())
+}
+
+fn hex(bytes: &[u8]) -> String {
+    bytes.iter().map(|byte| format!("{byte:02x}")).collect()
+}

src/federation/mod.rs

@@ -0,0 +1,991 @@
+//! P2P federation for the furumusic server.
+//!
+//! When enabled in the admin settings, the server becomes a regular peer of
+//! the furumi federation: it publishes its whole visible library (artists,
+//! releases, tracks — names and small metadata, never files) into the
+//! shared DHT and serves audio, track metadata, cover art and per-artist
+//! catalogs to other peers (TUI clients) over the same wire protocols the
+//! clients speak among themselves. Serve-only: the server does not search
+//! or download from other peers.
+//!
+//! Settings are the regular admin config entries (`federation_enabled`,
+//! `federation_network_id`, `federation_save_on_listen`) and apply on the fly — saving the settings
+//! starts, stops or re-joins the node without a server restart.
+
+pub mod client;
+pub mod devices;
+mod receive;
+mod serve;
+mod storage;
+
+use std::collections::{HashMap, HashSet, VecDeque};
+use std::path::PathBuf;
+use std::sync::{Arc, OnceLock};
+use std::time::Duration;
+
+use anyhow::{Context, Result};
+use music_dht::{
+    ByteStream, ByteStreamConnectionStats, ItemKind, ItemSpec, MusicDhtConfig, MusicDhtService,
+    NetworkId, PeerTicket, PublishStats, RendezvousConfig, SyncStats,
+};
+use serde_json::{Value, json};
+use sqlx::PgPool;
+use sqlx::Row as _;
+
+use crate::config::AppConfig;
+use storage::PostgresFederationStorage;
+
+pub use serve::{AUDIO_ALPN, CATALOG_ALPN};
+
+/// How often the published library is re-synchronized with the database.
+const SYNC_INTERVAL: Duration = Duration::from_secs(60);
+const TRANSPORT_SAMPLE_LIMIT: usize = 16;
+
+struct Running {
+    service: Arc<MusicDhtService>,
+    network_name: String,
+    tasks: Vec<tokio::task::JoinHandle<()>>,
+}
+
+struct ContentHashJob {
+    media_file_id: i64,
+    sha256_hash: String,
+    file_path: String,
+}
+
+#[derive(Clone)]
+struct CachedArtwork {
+    bytes: Vec<u8>,
+    mime: String,
+    fetched_at: std::time::Instant,
+}
+
+#[derive(Debug, Clone)]
+struct TransportSample {
+    at: String,
+    protocol: &'static str,
+    direction: &'static str,
+    phase: &'static str,
+    peer_id: String,
+    selected_path: String,
+    open_paths: usize,
+    direct_paths: usize,
+    relay_paths: usize,
+    custom_paths: usize,
+    selected_rtt_ms: Option<u64>,
+    selected_tx_bytes: u64,
+    selected_rx_bytes: u64,
+    total_tx_bytes: u64,
+    total_rx_bytes: u64,
+    lost_packets: u64,
+    lost_bytes: u64,
+}
+
+impl TransportSample {
+    fn from_stats(
+        protocol: &'static str,
+        direction: &'static str,
+        phase: &'static str,
+        stats: ByteStreamConnectionStats,
+    ) -> Self {
+        Self {
+            at: now_iso(),
+            protocol,
+            direction,
+            phase,
+            peer_id: stats.peer_id.to_string(),
+            selected_path: stats.selected_path.as_str().to_string(),
+            open_paths: stats.open_paths,
+            direct_paths: stats.direct_paths,
+            relay_paths: stats.relay_paths,
+            custom_paths: stats.custom_paths,
+            selected_rtt_ms: stats
+                .selected_rtt
+                .map(|duration| duration.as_millis() as u64),
+            selected_tx_bytes: stats.selected_tx_bytes,
+            selected_rx_bytes: stats.selected_rx_bytes,
+            total_tx_bytes: stats.total_tx_bytes,
+            total_rx_bytes: stats.total_rx_bytes,
+            lost_packets: stats.lost_packets,
+            lost_bytes: stats.lost_bytes,
+        }
+    }
+}
+
+#[derive(Debug, Default)]
+struct TransportStatsState {
+    total_samples: u64,
+    direct_samples: u64,
+    relay_samples: u64,
+    custom_samples: u64,
+    unknown_samples: u64,
+    audio_samples: u64,
+    catalog_samples: u64,
+    sync_samples: u64,
+    last: VecDeque<TransportSample>,
+}
+
+#[derive(Debug, Default)]
+pub struct TransportStats {
+    inner: std::sync::Mutex<TransportStatsState>,
+}
+
+impl TransportStats {
+    fn reset(&self) {
+        *lock(&self.inner) = TransportStatsState::default();
+    }
+
+    fn record(
+        &self,
+        protocol: &'static str,
+        direction: &'static str,
+        phase: &'static str,
+        stats: ByteStreamConnectionStats,
+    ) {
+        let sample = TransportSample::from_stats(protocol, direction, phase, stats);
+        let mut state = lock(&self.inner);
+        state.total_samples += 1;
+        match sample.selected_path.as_str() {
+            "direct" => state.direct_samples += 1,
+            "relay" => state.relay_samples += 1,
+            "custom" => state.custom_samples += 1,
+            _ => state.unknown_samples += 1,
+        }
+        match protocol {
+            "audio" => state.audio_samples += 1,
+            "catalog" => state.catalog_samples += 1,
+            "device-sync" => state.sync_samples += 1,
+            _ => {}
+        }
+        state.last.push_front(sample);
+        while state.last.len() > TRANSPORT_SAMPLE_LIMIT {
+            state.last.pop_back();
+        }
+    }
+
+    fn snapshot(&self) -> Value {
+        let state = lock(&self.inner);
+        let latest = state.last.front();
+        json!({
+            "total_samples": state.total_samples,
+            "direct_samples": state.direct_samples,
+            "relay_samples": state.relay_samples,
+            "custom_samples": state.custom_samples,
+            "unknown_samples": state.unknown_samples,
+            "audio_samples": state.audio_samples,
+            "catalog_samples": state.catalog_samples,
+            "sync_samples": state.sync_samples,
+            "last_path": latest.map(|sample| sample.selected_path.clone()),
+            "last_rtt_ms": latest.and_then(|sample| sample.selected_rtt_ms),
+            "last_peer": latest.map(|sample| sample.peer_id.clone()),
+            "last": state.last.iter().map(|sample| json!({
+                "at": sample.at,
+                "protocol": sample.protocol,
+                "direction": sample.direction,
+                "phase": sample.phase,
+                "peer_id": sample.peer_id,
+                "selected_path": sample.selected_path,
+                "open_paths": sample.open_paths,
+                "direct_paths": sample.direct_paths,
+                "relay_paths": sample.relay_paths,
+                "custom_paths": sample.custom_paths,
+                "selected_rtt_ms": sample.selected_rtt_ms,
+                "selected_tx_bytes": sample.selected_tx_bytes,
+                "selected_rx_bytes": sample.selected_rx_bytes,
+                "total_tx_bytes": sample.total_tx_bytes,
+                "total_rx_bytes": sample.total_rx_bytes,
+                "lost_packets": sample.lost_packets,
+                "lost_bytes": sample.lost_bytes,
+            })).collect::<Vec<_>>(),
+        })
+    }
+}
+
+pub fn record_stream_transport(
+    stats: &Arc<TransportStats>,
+    protocol: &'static str,
+    direction: &'static str,
+    phase: &'static str,
+    stream: &ByteStream,
+) {
+    stats.record(protocol, direction, phase, stream.connection_stats());
+}
+
+pub struct Federation {
+    /// Transport data directory; server-side DHT state and identity live in PostgreSQL.
+    data_dir: PathBuf,
+    database_url: std::sync::Mutex<String>,
+    storage_dir: std::sync::Mutex<String>,
+    save_on_listen: std::sync::atomic::AtomicBool,
+    content_cache: std::sync::Mutex<HashMap<i64, (String, String)>>,
+    content_pending: std::sync::Mutex<HashSet<i64>>,
+    prepared_cache: std::sync::Mutex<HashMap<String, (PathBuf, String)>>,
+    artwork_cache: std::sync::Mutex<HashMap<String, CachedArtwork>>,
+    download_locks: std::sync::Mutex<HashMap<String, Arc<tokio::sync::Mutex<()>>>>,
+    pool: tokio::sync::OnceCell<PgPool>,
+    running: tokio::sync::Mutex<Option<Running>>,
+    last_sync: std::sync::Mutex<Option<String>>,
+    last_error: std::sync::Mutex<Option<String>>,
+    transport_stats: Arc<TransportStats>,
+}
+
+fn now_iso() -> String {
+    chrono::Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string()
+}
+
+fn lock<T>(mutex: &std::sync::Mutex<T>) -> std::sync::MutexGuard<'_, T> {
+    mutex
+        .lock()
+        .unwrap_or_else(std::sync::PoisonError::into_inner)
+}
+
+/// The process-wide federation handle.
+pub fn handle() -> Arc<Federation> {
+    static HANDLE: OnceLock<Arc<Federation>> = OnceLock::new();
+    Arc::clone(HANDLE.get_or_init(|| {
+        Arc::new(Federation {
+            data_dir: PathBuf::from(crate::media_paths::resolve_config_path("federation")),
+            database_url: std::sync::Mutex::new(String::new()),
+            storage_dir: std::sync::Mutex::new(String::new()),
+            save_on_listen: std::sync::atomic::AtomicBool::new(false),
+            content_cache: std::sync::Mutex::new(Default::default()),
+            content_pending: std::sync::Mutex::new(Default::default()),
+            prepared_cache: std::sync::Mutex::new(Default::default()),
+            artwork_cache: std::sync::Mutex::new(Default::default()),
+            download_locks: std::sync::Mutex::new(Default::default()),
+            pool: tokio::sync::OnceCell::new(),
+            running: tokio::sync::Mutex::new(None),
+            last_sync: std::sync::Mutex::new(None),
+            last_error: std::sync::Mutex::new(None),
+            transport_stats: Arc::new(TransportStats::default()),
+        })
+    }))
+}
+
+impl Federation {
+    fn set_error(&self, message: Option<String>) {
+        *lock(&self.last_error) = message;
+    }
+
+    async fn pool(&self) -> Result<PgPool> {
+        let url = lock(&self.database_url).clone();
+        anyhow::ensure!(!url.is_empty(), "database is not configured");
+        let pool = self
+            .pool
+            .get_or_try_init(|| async {
+                sqlx::postgres::PgPoolOptions::new()
+                    .max_connections(4)
+                    .connect(&url)
+                    .await
+            })
+            .await?;
+        Ok(pool.clone())
+    }
+
+    /// Starts the node at boot when federation was left enabled. The
+    /// settings live in the config KV table, so this waits for the database
+    /// and resolves the same default → DB → env precedence the config uses.
+    pub async fn boot(self: &Arc<Self>, config: &AppConfig) {
+        *lock(&self.database_url) = config.database_url.clone();
+        if config.database_url.is_empty() {
+            return;
+        }
+        let pool = match self.pool().await {
+            Ok(pool) => pool,
+            Err(err) => {
+                tracing::warn!("federation boot: database unavailable: {err:#}");
+                return;
+            }
+        };
+        // `config` carries defaults + env; overlay the DB rows for fields
+        // that have no env override (env > DB > default).
+        let mut effective = config.clone();
+        let rows = sqlx::query(
+            "SELECT key, value FROM furumusic__config_entry
+             WHERE key IN ('federation_enabled', 'federation_network_id',
+                           'federation_save_on_listen', 'agent_storage_dir')",
+        )
+        .fetch_all(&pool)
+        .await
+        .unwrap_or_default();
+        for row in rows {
+            let key: String = row.get(0);
+            let value: String = row.get(1);
+            let env_key = format!("FURU_{}", key.to_ascii_uppercase());
+            if std::env::var(&env_key).is_ok() {
+                continue;
+            }
+            match key.as_str() {
+                "federation_enabled" => {
+                    if let Ok(parsed) = value.parse() {
+                        effective.federation_enabled = parsed;
+                    }
+                }
+                "federation_network_id" => effective.federation_network_id = value,
+                "federation_save_on_listen" => {
+                    if let Ok(parsed) = value.parse() {
+                        effective.federation_save_on_listen = parsed;
+                    }
+                }
+                "agent_storage_dir" => {
+                    effective.agent_storage_dir = crate::media_paths::resolve_config_path(&value);
+                }
+                _ => {}
+            }
+        }
+        self.apply(&effective).await;
+    }
+
+    /// Applies the effective configuration: starts, stops or re-joins the
+    /// node. Called at boot and every time the admin settings are saved.
+    pub async fn apply(self: &Arc<Self>, config: &AppConfig) {
+        *lock(&self.database_url) = config.database_url.clone();
+        *lock(&self.storage_dir) = config.agent_storage_dir.clone();
+        self.save_on_listen.store(
+            config.federation_save_on_listen,
+            std::sync::atomic::Ordering::Relaxed,
+        );
+        let network = config.federation_network_id.trim().to_string();
+        if config.federation_enabled && !network.is_empty() {
+            if let Err(err) = self.start(network, config.agent_storage_dir.clone()).await {
+                tracing::error!("federation start failed: {err:#}");
+                self.set_error(Some(format!("start failed: {err}")));
+            }
+        } else {
+            self.stop().await;
+        }
+    }
+
+    /// Starts the DHT node. Idempotent per network name; a node on another
+    /// network is stopped and re-joined.
+    async fn start(self: &Arc<Self>, network_name: String, storage_dir: String) -> Result<()> {
+        let pool = self.pool().await?;
+        let mut guard = self.running.lock().await;
+        if let Some(running) = guard.as_ref() {
+            if running.network_name == network_name {
+                return Ok(());
+            }
+            stop_running(guard.take()).await;
+        }
+
+        let dht_storage = Arc::new(PostgresFederationStorage::new(pool.clone()).await?);
+        let secret_key = dht_storage.load_or_create_secret_key().await?;
+        self.transport_stats.reset();
+
+        let config = MusicDhtConfig::builder()
+            .data_dir(&self.data_dir)
+            .network_id(NetworkId::from_name(&network_name))
+            // Peers of the network find each other knowing only its name.
+            .rendezvous(RendezvousConfig::default())
+            .stream_protocol(AUDIO_ALPN)
+            .stream_protocol(CATALOG_ALPN)
+            .stream_protocol(devices::SYNC_ALPN)
+            .build()
+            .map_err(|err| anyhow::anyhow!("invalid federation config: {err}"))?;
+        let (service, mut events) =
+            MusicDhtService::start_with_storage_and_secret_key(config, dht_storage, secret_key)
+                .await
+                .map_err(|err| anyhow::anyhow!("failed to start the DHT node: {err}"))?;
+        let service = Arc::new(service);
+        tracing::info!(
+            endpoint_id = %service.endpoint_id(),
+            network = %network_name,
+            "federation started"
+        );
+
+        // Drain DHT events into the log; the channel is bounded.
+        let event_task = tokio::spawn(async move {
+            while let Some(event) = events.recv().await {
+                tracing::debug!("federation event: {event:?}");
+            }
+        });
+        // Keep the published library in sync with the database.
+        let sync_self = Arc::clone(self);
+        let sync_service = Arc::clone(&service);
+        let sync_task = tokio::spawn(async move {
+            let mut interval = tokio::time::interval(SYNC_INTERVAL);
+            loop {
+                interval.tick().await;
+                let _ = sync_self.sync_once(&sync_service).await;
+            }
+        });
+        // Serve audio and catalog requests from other peers.
+        let audio_acceptor = service
+            .stream_acceptor(AUDIO_ALPN)
+            .map_err(|err| anyhow::anyhow!("failed to take the audio acceptor: {err}"))?;
+        let audio_task = tokio::spawn(serve::serve_audio(
+            audio_acceptor,
+            pool.clone(),
+            storage_dir.clone(),
+            service.endpoint_id(),
+            Arc::clone(&self.transport_stats),
+        ));
+        let catalog_acceptor = service
+            .stream_acceptor(CATALOG_ALPN)
+            .map_err(|err| anyhow::anyhow!("failed to take the catalog acceptor: {err}"))?;
+        let catalog_task = tokio::spawn(serve::serve_catalog(
+            catalog_acceptor,
+            pool.clone(),
+            storage_dir,
+            service.endpoint_id(),
+            Arc::clone(&self.transport_stats),
+        ));
+        let device_acceptor = service
+            .stream_acceptor(devices::SYNC_ALPN)
+            .map_err(|err| anyhow::anyhow!("failed to take the device-sync acceptor: {err}"))?;
+        let device_hub = crate::player::PlayerDeviceHub::shared();
+        let device_task = tokio::spawn(devices::serve_peers(
+            device_acceptor,
+            pool.clone(),
+            Arc::clone(&service),
+            Arc::clone(&device_hub),
+            Arc::clone(&self.transport_stats),
+        ));
+        let device_sync_task = tokio::spawn(devices::sync_loop(
+            pool,
+            Arc::clone(&service),
+            device_hub,
+            Arc::clone(&self.transport_stats),
+        ));
+
+        *guard = Some(Running {
+            service,
+            network_name,
+            tasks: vec![
+                event_task,
+                sync_task,
+                audio_task,
+                catalog_task,
+                device_task,
+                device_sync_task,
+            ],
+        });
+        self.set_error(None);
+        drop(guard);
+        // Publish right away instead of waiting for the first timer tick.
+        self.spawn_sync_soon().await;
+        Ok(())
+    }
+
+    async fn stop(&self) {
+        let mut guard = self.running.lock().await;
+        stop_running(guard.take()).await;
+    }
+
+    async fn service(&self) -> Result<Arc<MusicDhtService>> {
+        self.running
+            .lock()
+            .await
+            .as_ref()
+            .map(|running| Arc::clone(&running.service))
+            .context("federation is not running")
+    }
+
+    async fn spawn_sync_soon(self: &Arc<Self>) {
+        if let Ok(service) = self.service().await {
+            let fed = Arc::clone(self);
+            tokio::spawn(async move {
+                let _ = fed.sync_once(&service).await;
+            });
+        }
+    }
+
+    pub async fn sync_now(self: &Arc<Self>) -> Result<()> {
+        let service = self.service().await?;
+        let sync_stats = self.sync_once(&service).await?;
+        let publish_stats = match service.republish().await {
+            Ok(stats) => stats,
+            Err(err) => {
+                tracing::warn!("federation republish failed: {err}");
+                self.set_error(Some(format!("republish failed: {err}")));
+                anyhow::bail!("republish failed: {err}");
+            }
+        };
+        self.record_publish_success(sync_stats, publish_stats);
+        Ok(())
+    }
+
+    async fn sync_once(self: &Arc<Self>, service: &MusicDhtService) -> Result<SyncStats> {
+        let specs = match self.collect_specs().await {
+            Ok(specs) => specs,
+            Err(err) => {
+                tracing::warn!("federation sync: library read failed: {err:#}");
+                self.set_error(Some(format!("library read failed: {err}")));
+                anyhow::bail!("library read failed: {err}");
+            }
+        };
+        match service.sync_library(specs).await {
+            Ok(stats) => {
+                self.record_sync_success(stats);
+                if stats.failed > 0 {
+                    self.set_error(Some(format!(
+                        "{} item(s) failed to publish in the last sync",
+                        stats.failed
+                    )));
+                } else {
+                    self.set_error(None);
+                }
+                Ok(stats)
+            }
+            Err(err) => {
+                tracing::warn!("federation sync failed: {err}");
+                self.set_error(Some(format!("sync failed: {err}")));
+                Err(anyhow::anyhow!("sync failed: {err}"))
+            }
+        }
+    }
+
+    fn record_sync_success(&self, stats: SyncStats) {
+        *lock(&self.last_sync) = Some(format!(
+            "{} (+{} ~{} −{}, unchanged {}, failed {})",
+            now_iso(),
+            stats.added,
+            stats.updated,
+            stats.removed,
+            stats.unchanged,
+            stats.failed
+        ));
+    }
+
+    fn record_publish_success(&self, sync_stats: SyncStats, publish_stats: PublishStats) {
+        *lock(&self.last_sync) = Some(format!(
+            "{} (+{} ~{} −{}, unchanged {}, failed {}; republished {} records, {} keys, remote nodes {})",
+            now_iso(),
+            sync_stats.added,
+            sync_stats.updated,
+            sync_stats.removed,
+            sync_stats.unchanged,
+            sync_stats.failed,
+            publish_stats.records,
+            publish_stats.keys,
+            publish_stats.remote_nodes,
+        ));
+        self.set_error(None);
+    }
+
+    /// Everything the regular player shows, as DHT item specs: non-hidden
+    /// artists, releases and tracks (a track also hides with its release).
+    async fn collect_specs(self: &Arc<Self>) -> Result<Vec<ItemSpec>> {
+        let pool = self.pool().await?;
+        let mut specs = Vec::new();
+
+        let artists = sqlx::query("SELECT id, name FROM furumusic__artist WHERE is_hidden = false")
+            .fetch_all(&pool)
+            .await?;
+        for row in &artists {
+            let id: i64 = row.get(0);
+            specs.push(ItemSpec {
+                local_key: format!("artist:{id}"),
+                kind: ItemKind::Artist,
+                name: row.get(1),
+                artist_names: Vec::new(),
+                featured_artist_names: Vec::new(),
+                year: None,
+                release_type: None,
+                release_title: None,
+                track_number: None,
+                disc_number: None,
+                duration_seconds: None,
+                content_id: None,
+            });
+        }
+
+        let release_artists = sqlx::query(
+            "SELECT ra.release_id, a.name FROM furumusic__release_artist ra
+             JOIN furumusic__artist a ON a.id = ra.artist_id
+             ORDER BY ra.release_id, ra.position",
+        )
+        .fetch_all(&pool)
+        .await?;
+        let mut artists_of_release: std::collections::HashMap<i64, Vec<String>> =
+            Default::default();
+        for row in &release_artists {
+            artists_of_release
+                .entry(row.get(0))
+                .or_default()
+                .push(row.get(1));
+        }
+        let releases = sqlx::query(
+            "SELECT id, title, year, release_type FROM furumusic__release
+             WHERE is_hidden = false",
+        )
+        .fetch_all(&pool)
+        .await?;
+        for row in &releases {
+            let id: i64 = row.get(0);
+            specs.push(ItemSpec {
+                local_key: format!("release:{id}"),
+                kind: ItemKind::Release,
+                name: row.get(1),
+                artist_names: artists_of_release.remove(&id).unwrap_or_default(),
+                featured_artist_names: Vec::new(),
+                year: row.get(2),
+                release_type: row.get(3),
+                release_title: None,
+                track_number: None,
+                disc_number: None,
+                duration_seconds: None,
+                content_id: None,
+            });
+        }
+
+        let track_artists = sqlx::query(
+            "SELECT ta.track_id, a.name, ta.role FROM furumusic__track_artist ta
+             JOIN furumusic__artist a ON a.id = ta.artist_id
+             WHERE ta.role IN ('main', 'featuring')
+             ORDER BY ta.track_id,
+                      CASE ta.role WHEN 'main' THEN 0 ELSE 1 END,
+                      ta.position",
+        )
+        .fetch_all(&pool)
+        .await?;
+        let mut artists_of_track: std::collections::HashMap<i64, Vec<String>> = Default::default();
+        let mut featured_of_track: std::collections::HashMap<i64, Vec<String>> = Default::default();
+        for row in &track_artists {
+            let id: i64 = row.get(0);
+            let name: String = row.get(1);
+            if row.get::<String, _>(2) == "featuring" {
+                featured_of_track.entry(id).or_default().push(name);
+            } else {
+                artists_of_track.entry(id).or_default().push(name);
+            }
+        }
+        let tracks = sqlx::query(
+            "SELECT t.id, t.title, COALESCE(t.year, r.year), t.duration_seconds,
+                    r.title, r.release_type, t.track_number, t.disc_number,
+                    t.audio_file_id, m.file_path, m.sha256_hash, c.content_id
+             FROM furumusic__track t
+             JOIN furumusic__release r ON r.id = t.release_id
+             JOIN furumusic__media_file m ON m.id = t.audio_file_id
+             LEFT JOIN furumusic__federation_content_id_cache c
+                    ON c.media_file_id = m.id AND c.sha256_hash = m.sha256_hash
+             WHERE t.is_hidden = false AND r.is_hidden = false",
+        )
+        .fetch_all(&pool)
+        .await?;
+        let storage_dir = lock(&self.storage_dir).clone();
+        let mut content_hash_jobs = Vec::new();
+        for row in &tracks {
+            let id: i64 = row.get(0);
+            let duration: f64 = row.get(3);
+            let media_file_id: i64 = row.get(8);
+            let file_path: String = row.get(9);
+            let sha256_hash: String = row.get(10);
+            let cached_content_id: Option<String> = row.get(11);
+            let content_id = cached_content_id
+                .or_else(|| self.cached_content_id_for_media(media_file_id, &sha256_hash));
+            if content_id.is_none()
+                && !storage_dir.trim().is_empty()
+                && self.mark_content_hash_pending(media_file_id)
+            {
+                content_hash_jobs.push(ContentHashJob {
+                    media_file_id,
+                    sha256_hash,
+                    file_path,
+                });
+            }
+            specs.push(ItemSpec {
+                local_key: format!("track:{id}"),
+                kind: ItemKind::Track,
+                name: row.get(1),
+                artist_names: artists_of_track.remove(&id).unwrap_or_default(),
+                featured_artist_names: featured_of_track.remove(&id).unwrap_or_default(),
+                year: row.get(2),
+                release_type: row.get(5),
+                release_title: Some(row.get(4)),
+                track_number: row.get(6),
+                disc_number: row.get(7),
+                duration_seconds: (duration > 0.0).then_some(duration),
+                content_id,
+            });
+        }
+        self.spawn_content_warmer(pool.clone(), storage_dir, content_hash_jobs);
+
+        Ok(specs)
+    }
+
+    fn cached_content_id_for_media(&self, media_file_id: i64, sha256_hash: &str) -> Option<String> {
+        if let Some((cached_hash, content_id)) = lock(&self.content_cache).get(&media_file_id)
+            && cached_hash == sha256_hash
+        {
+            return Some(content_id.clone());
+        }
+        None
+    }
+
+    fn mark_content_hash_pending(&self, media_file_id: i64) -> bool {
+        lock(&self.content_pending).insert(media_file_id)
+    }
+
+    fn spawn_content_warmer(
+        self: &Arc<Self>,
+        pool: PgPool,
+        storage_dir: String,
+        jobs: Vec<ContentHashJob>,
+    ) {
+        if jobs.is_empty() {
+            return;
+        }
+        let fed = Arc::clone(self);
+        tokio::spawn(async move {
+            let total = jobs.len();
+            let mut stored = 0usize;
+            for job in jobs {
+                let job_storage_dir = storage_dir.clone();
+                let job_file_path = job.file_path.clone();
+                let content_id = tokio::task::spawn_blocking(move || {
+                    audio_content_id(&job_storage_dir, &job_file_path)
+                })
+                .await
+                .ok()
+                .flatten();
+                lock(&fed.content_pending).remove(&job.media_file_id);
+                if let Some(content_id) = content_id {
+                    lock(&fed.content_cache).insert(
+                        job.media_file_id,
+                        (job.sha256_hash.clone(), content_id.clone()),
+                    );
+                    if let Err(err) =
+                        persist_content_id(&pool, job.media_file_id, &job.sha256_hash, &content_id)
+                            .await
+                    {
+                        tracing::warn!(
+                            media_file_id = job.media_file_id,
+                            "federation content-id cache write failed: {err:#}"
+                        );
+                    } else {
+                        stored += 1;
+                    }
+                }
+            }
+            tracing::info!(total, stored, "federation content-id cache warm finished");
+        });
+    }
+
+    /// Live status for the admin page.
+    pub async fn status(&self) -> Value {
+        let guard = self.running.lock().await;
+        let node = match guard.as_ref() {
+            Some(running) => {
+                let service = &running.service;
+                let published = service
+                    .list_local_items()
+                    .await
+                    .map(|items| items.len())
+                    .unwrap_or(0);
+                let peers: Vec<String> = service
+                    .connected_peers()
+                    .iter()
+                    .map(|p| p.to_string())
+                    .collect();
+                json!({
+                    "running": true,
+                    "network": running.network_name,
+                    "endpoint_id": service.endpoint_id().to_string(),
+                    "connected_peers": peers,
+                    "known_contacts": service.known_peers().len(),
+                    "published_items": published,
+                    "transport": self.transport_stats.snapshot(),
+                })
+            }
+            None => json!({ "running": false }),
+        };
+        json!({
+            "node": node,
+            "last_sync": lock(&self.last_sync).clone(),
+            "last_error": lock(&self.last_error).clone(),
+        })
+    }
+
+    pub async fn ticket(&self) -> Result<String> {
+        let service = self.service().await?;
+        let ticket = service
+            .ticket()
+            .await
+            .map_err(|err| anyhow::anyhow!("cannot create a ticket: {err}"))?;
+        Ok(ticket.to_string())
+    }
+
+    pub async fn connect(&self, ticket: &str) -> Result<String> {
+        let service = self.service().await?;
+        let ticket: PeerTicket = ticket
+            .trim()
+            .parse()
+            .map_err(|err| anyhow::anyhow!("malformed ticket: {err}"))?;
+        let peer = service
+            .connect(ticket)
+            .await
+            .map_err(|err| anyhow::anyhow!("connect failed: {err}"))?;
+        Ok(peer.to_string())
+    }
+
+    pub async fn fed_device_status(
+        &self,
+        user_id: i64,
+        user_name: &str,
+    ) -> Result<devices::FedDeviceStatus> {
+        let pool = self.pool().await?;
+        devices::status(&pool, user_id, user_name).await
+    }
+
+    pub async fn fed_device_invite(&self, user_id: i64, user_name: &str) -> Result<String> {
+        let service = self.service().await?;
+        let pool = self.pool().await?;
+        devices::create_invite(&pool, service, user_id, user_name).await
+    }
+
+    pub async fn fed_device_connect(
+        &self,
+        user_id: i64,
+        user_name: &str,
+        invite: &str,
+    ) -> Result<String> {
+        let network_id = devices::invite_network_id(invite)?;
+        {
+            let guard = self.running.lock().await;
+            let Some(running) = guard.as_ref() else {
+                anyhow::bail!("federation is not running");
+            };
+            let expected = NetworkId::from_name(&running.network_name);
+            anyhow::ensure!(
+                network_id == expected,
+                "device invite belongs to a different federation network"
+            );
+        }
+        let service = self.service().await?;
+        let pool = self.pool().await?;
+        devices::connect_invite(
+            &pool,
+            service,
+            crate::player::PlayerDeviceHub::shared(),
+            Arc::clone(&self.transport_stats),
+            user_id,
+            user_name,
+            invite,
+        )
+        .await
+    }
+
+    pub async fn fed_device_answer_pairing(
+        &self,
+        user_id: i64,
+        request_id: &str,
+        accept: bool,
+        use_requester_group: bool,
+    ) -> Result<()> {
+        let pool = self.pool().await?;
+        devices::answer_pairing(&pool, user_id, request_id, accept, use_requester_group).await
+    }
+
+    pub async fn fed_device_revoke(&self, user_id: i64, device_id: &str) -> Result<()> {
+        let pool = self.pool().await?;
+        devices::revoke_device(&pool, user_id, device_id).await
+    }
+
+    pub async fn fed_device_sync_now(&self, user_id: i64) -> Result<()> {
+        let service = self.service().await?;
+        let pool = self.pool().await?;
+        devices::sync_once(
+            &pool,
+            service,
+            crate::player::PlayerDeviceHub::shared(),
+            Arc::clone(&self.transport_stats),
+            user_id,
+        )
+        .await
+    }
+
+    pub async fn fed_device_web_command(
+        &self,
+        user_id: i64,
+        target_device_id: &str,
+        command: &str,
+        payload: serde_json::Value,
+        current_state: Option<serde_json::Value>,
+    ) -> Result<serde_json::Value> {
+        let pool = self.pool().await?;
+        devices::record_web_playback_command(
+            &pool,
+            user_id,
+            target_device_id,
+            command,
+            payload,
+            current_state,
+        )
+        .await
+    }
+
+    pub async fn fed_device_web_active_transfer(
+        &self,
+        user_id: i64,
+        target_device_id: &str,
+        previous_device_id: Option<&str>,
+        state: serde_json::Value,
+    ) -> Result<()> {
+        let pool = self.pool().await?;
+        devices::record_web_active_transfer(
+            &pool,
+            user_id,
+            target_device_id,
+            previous_device_id,
+            state,
+        )
+        .await
+    }
+
+    pub async fn fed_device_web_active_takeover(
+        &self,
+        user_id: i64,
+        previous_device_id: &str,
+        state: serde_json::Value,
+    ) -> Result<()> {
+        let pool = self.pool().await?;
+        devices::record_web_active_takeover(&pool, user_id, previous_device_id, state).await
+    }
+}
+
+async fn persist_content_id(
+    pool: &PgPool,
+    media_file_id: i64,
+    sha256_hash: &str,
+    content_id: &str,
+) -> Result<()> {
+    sqlx::query(
+        "INSERT INTO furumusic__federation_content_id_cache
+         (media_file_id, sha256_hash, content_id, updated_at)
+         VALUES ($1, $2, $3, $4)
+         ON CONFLICT (media_file_id) DO UPDATE SET
+            sha256_hash = EXCLUDED.sha256_hash,
+            content_id = EXCLUDED.content_id,
+            updated_at = EXCLUDED.updated_at",
+    )
+    .bind(media_file_id)
+    .bind(sha256_hash)
+    .bind(content_id)
+    .bind(now_iso())
+    .execute(pool)
+    .await?;
+    Ok(())
+}
+
+fn audio_content_id(storage_dir: &str, file_path: &str) -> Option<String> {
+    if storage_dir.trim().is_empty() {
+        return None;
+    }
+    let path = crate::media_paths::resolve_media_file_path(storage_dir, file_path);
+    let mut file = std::fs::File::open(path).ok()?;
+    let mut hasher = blake3::Hasher::new();
+    std::io::copy(&mut file, &mut hasher).ok()?;
+    Some(format!("b3:{}", hasher.finalize().to_hex()))
+}
+
+async fn stop_running(running: Option<Running>) {
+    let Some(running) = running else { return };
+    for task in &running.tasks {
+        task.abort();
+    }
+    if let Err(err) = running.service.shutdown().await {
+        tracing::warn!("federation node shutdown reported an error: {err}");
+    }
+    tracing::info!("federation stopped");
+}

src/federation/serve.rs

@@ -0,0 +1,773 @@
+//! Serve side of the federation wire protocols (audio + catalog), backed by
+//! the PostgreSQL library and the media storage directory. Wire compatible
+//! with the furumi TUI client and any other furumi peer.
+
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+use anyhow::Result;
+pub use music_dht::catalog::CATALOG_ALPN;
+use music_dht::catalog::{
+    CatalogArtist, CatalogArtistPreview, CatalogImageHeader as ImageHeader, CatalogRelease,
+    CatalogRequest, CatalogResponse, CatalogTrack,
+};
+use music_dht::{ByteStream, EndpointId, ItemId, ItemKind, StreamAcceptor, normalize_name};
+use serde::{Deserialize, Serialize};
+use sqlx::PgPool;
+use sqlx::Row as _;
+use tokio::io::{AsyncRead, AsyncReadExt, AsyncSeekExt, AsyncWriteExt};
+
+use super::{TransportStats, record_stream_transport};
+
+/// ALPN of the peer-to-peer audio streaming protocol.
+pub const AUDIO_ALPN: &[u8] = b"furumi-fd/audio/1";
+
+/// Maximum size of a JSON protocol line (request or response header).
+const MAX_PROTOCOL_LINE: usize = 4096;
+/// Images above this size are skipped rather than transferred.
+const MAX_IMAGE_BYTES: u64 = 16 * 1024 * 1024;
+
+// ---------------------------------------------------------------------------
+// Wire shapes (shared with the furumi TUI client)
+// ---------------------------------------------------------------------------
+
+#[derive(Debug, Deserialize)]
+struct AudioRequest {
+    item_id: String,
+    #[serde(default)]
+    offset: u64,
+    #[serde(default)]
+    want_cover: bool,
+}
+
+#[derive(Debug, Default, Serialize)]
+struct AudioResponseHeader {
+    ok: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    error: Option<String>,
+    mime_type: String,
+    total_size: u64,
+    offset: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    metadata: Option<TrackMetadata>,
+    cover_size: u64,
+    cover_mime: String,
+    artist_image_size: u64,
+    artist_image_mime: String,
+}
+
+#[derive(Debug, Clone, Default, Serialize)]
+struct TrackMetadata {
+    title: String,
+    artists: Vec<String>,
+    featured_artists: Vec<String>,
+    album_artists: Vec<String>,
+    release_title: String,
+    release_type: Option<String>,
+    year: Option<i32>,
+    track_number: Option<i32>,
+    disc_number: Option<i32>,
+}
+
+// ---------------------------------------------------------------------------
+// Framing helpers
+// ---------------------------------------------------------------------------
+
+fn hex_encode(bytes: &[u8]) -> String {
+    bytes.iter().map(|b| format!("{b:02x}")).collect()
+}
+
+fn hex_decode_item_id(value: &str) -> Option<ItemId> {
+    if value.len() != 64 {
+        return None;
+    }
+    let mut bytes = [0u8; 32];
+    for (i, byte) in bytes.iter_mut().enumerate() {
+        *byte = u8::from_str_radix(&value[i * 2..i * 2 + 2], 16).ok()?;
+    }
+    Some(ItemId::from_bytes(bytes))
+}
+
+async fn read_line<R: AsyncRead + Unpin>(reader: &mut R) -> Result<Vec<u8>> {
+    let mut line = Vec::new();
+    let mut byte = [0u8; 1];
+    loop {
+        let n = reader.read(&mut byte).await?;
+        if n == 0 {
+            anyhow::bail!("stream ended before the protocol line was complete");
+        }
+        if byte[0] == b'\n' {
+            return Ok(line);
+        }
+        line.push(byte[0]);
+        if line.len() > MAX_PROTOCOL_LINE {
+            anyhow::bail!("protocol line exceeds {MAX_PROTOCOL_LINE} bytes");
+        }
+    }
+}
+
+async fn write_line<W: AsyncWriteExt + Unpin>(
+    writer: &mut W,
+    value: &impl Serialize,
+) -> Result<()> {
+    let mut line = serde_json::to_vec(value)?;
+    line.push(b'\n');
+    writer.write_all(&line).await?;
+    Ok(())
+}
+
+fn item_id_of(own: &EndpointId, track_id: i64) -> String {
+    hex_encode(ItemId::derive(own, ItemKind::Track, &format!("track:{track_id}")).as_bytes())
+}
+
+fn resolve_media_path(storage_dir: &str, file_path: &str) -> PathBuf {
+    crate::media_paths::resolve_media_file_path(storage_dir, file_path)
+}
+
+fn guess_mime(path: &Path) -> &'static str {
+    match path
+        .extension()
+        .and_then(|e| e.to_str())
+        .unwrap_or_default()
+        .to_ascii_lowercase()
+        .as_str()
+    {
+        "mp3" => "audio/mpeg",
+        "flac" => "audio/flac",
+        "ogg" | "oga" => "audio/ogg",
+        "opus" => "audio/opus",
+        "wav" => "audio/wav",
+        "m4a" | "mp4" | "alac" => "audio/mp4",
+        "aac" => "audio/aac",
+        "aiff" | "aif" => "audio/aiff",
+        _ => "application/octet-stream",
+    }
+}
+
+/// Reads an image media file from disk, bounded by [`MAX_IMAGE_BYTES`].
+async fn read_image(
+    storage_dir: &str,
+    media: Option<(String, String)>,
+) -> Option<(Vec<u8>, String)> {
+    let (file_path, mime) = media?;
+    let path = resolve_media_path(storage_dir, &file_path);
+    let size = tokio::fs::metadata(&path).await.ok()?.len();
+    if size == 0 || size > MAX_IMAGE_BYTES {
+        return None;
+    }
+    let bytes = tokio::fs::read(&path).await.ok()?;
+    let mime = if mime.trim().is_empty() {
+        "image/jpeg".to_string()
+    } else {
+        mime
+    };
+    Some((bytes, mime))
+}
+
+// ---------------------------------------------------------------------------
+// Library lookups (PostgreSQL)
+// ---------------------------------------------------------------------------
+
+/// Finds the visible track whose derived DHT item id matches `item_id`.
+async fn resolve_track_id(pool: &PgPool, own: &EndpointId, item_id: ItemId) -> Result<Option<i64>> {
+    let rows = sqlx::query(
+        "SELECT t.id FROM furumusic__track t
+         JOIN furumusic__release r ON r.id = t.release_id
+         WHERE t.is_hidden = false AND r.is_hidden = false",
+    )
+    .fetch_all(pool)
+    .await?;
+    for row in rows {
+        let track_id: i64 = row.get(0);
+        if ItemId::derive(own, ItemKind::Track, &format!("track:{track_id}")) == item_id {
+            return Ok(Some(track_id));
+        }
+    }
+    Ok(None)
+}
+
+/// (file_path, mime_type) of the track's audio media file.
+async fn track_audio_file(pool: &PgPool, track_id: i64) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__track t
+         JOIN furumusic__media_file m ON m.id = t.audio_file_id
+         WHERE t.id = $1",
+    )
+    .bind(track_id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}
+
+/// Track cover (falling back to the release cover) as (file_path, mime).
+async fn track_cover_file(pool: &PgPool, track_id: i64) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__track t
+         JOIN furumusic__release r ON r.id = t.release_id
+         JOIN furumusic__media_file m ON m.id = COALESCE(t.cover_file_id, r.cover_file_id)
+         WHERE t.id = $1",
+    )
+    .bind(track_id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}
+
+/// The main artist's image of a track as (file_path, mime).
+async fn track_artist_image_file(pool: &PgPool, track_id: i64) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__track_artist ta
+         JOIN furumusic__artist a ON a.id = ta.artist_id
+         JOIN furumusic__media_file m ON m.id = a.image_file_id
+         WHERE ta.track_id = $1 AND ta.role = 'main'
+         ORDER BY ta.position LIMIT 1",
+    )
+    .bind(track_id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}
+
+async fn track_catalog_artist_names(
+    pool: &PgPool,
+    track_id: i64,
+) -> Result<(Vec<String>, Vec<String>)> {
+    let mut artists = Vec::new();
+    let mut featured = Vec::new();
+    let rows = sqlx::query(
+        "SELECT a.name, ta.role FROM furumusic__track_artist ta
+         JOIN furumusic__artist a ON a.id = ta.artist_id
+         WHERE ta.track_id = $1 ORDER BY ta.position",
+    )
+    .bind(track_id)
+    .fetch_all(pool)
+    .await?;
+    for row in rows {
+        let name: String = row.get(0);
+        match row.get::<String, _>(1).as_str() {
+            "featuring" => featured.push(name),
+            "main" => artists.push(name),
+            _ => {}
+        }
+    }
+    Ok((artists, featured))
+}
+
+async fn track_metadata(pool: &PgPool, track_id: i64) -> Result<Option<TrackMetadata>> {
+    let Some(track) = sqlx::query(
+        "SELECT t.title, t.track_number, t.disc_number, COALESCE(t.year, r.year),
+                t.release_id, r.title, r.release_type
+         FROM furumusic__track t
+         JOIN furumusic__release r ON r.id = t.release_id
+         WHERE t.id = $1",
+    )
+    .bind(track_id)
+    .fetch_optional(pool)
+    .await?
+    else {
+        return Ok(None);
+    };
+    let release_id: i64 = track.get(4);
+
+    let mut artists = Vec::new();
+    let mut featured = Vec::new();
+    let artist_rows = sqlx::query(
+        "SELECT a.name, ta.role FROM furumusic__track_artist ta
+         JOIN furumusic__artist a ON a.id = ta.artist_id
+         WHERE ta.track_id = $1 ORDER BY ta.position",
+    )
+    .bind(track_id)
+    .fetch_all(pool)
+    .await?;
+    for row in artist_rows {
+        let name: String = row.get(0);
+        match row.get::<String, _>(1).as_str() {
+            "featuring" => featured.push(name),
+            "main" => artists.push(name),
+            _ => {}
+        }
+    }
+    let album_artists: Vec<String> = sqlx::query(
+        "SELECT a.name FROM furumusic__release_artist ra
+         JOIN furumusic__artist a ON a.id = ra.artist_id
+         WHERE ra.release_id = $1 ORDER BY ra.position",
+    )
+    .bind(release_id)
+    .fetch_all(pool)
+    .await?
+    .into_iter()
+    .map(|row| row.get(0))
+    .collect();
+
+    Ok(Some(TrackMetadata {
+        title: track.get(0),
+        artists,
+        featured_artists: featured,
+        album_artists,
+        release_title: track.get(5),
+        release_type: Some(track.get(6)),
+        year: track.get(3),
+        track_number: track.get(1),
+        disc_number: track.get(2),
+    }))
+}
+
+// ---------------------------------------------------------------------------
+// Audio protocol
+// ---------------------------------------------------------------------------
+
+/// Runs the audio accept loop until the acceptor closes. Every visible
+/// track of the library is streamable by every peer of the network.
+pub async fn serve_audio(
+    mut acceptor: StreamAcceptor,
+    pool: PgPool,
+    storage_dir: String,
+    own: EndpointId,
+    transport_stats: Arc<TransportStats>,
+) {
+    while let Some(stream) = acceptor.accept().await {
+        let pool = pool.clone();
+        let storage_dir = storage_dir.clone();
+        let transport_stats = Arc::clone(&transport_stats);
+        tokio::spawn(async move {
+            let peer = stream.peer_id;
+            if let Err(err) = serve_audio_one(stream, pool, storage_dir, own, transport_stats).await
+            {
+                tracing::warn!(peer = %peer, "federation audio stream failed: {err:#}");
+            }
+        });
+    }
+}
+
+async fn serve_audio_one(
+    mut stream: ByteStream,
+    pool: PgPool,
+    storage_dir: String,
+    own: EndpointId,
+    transport_stats: Arc<TransportStats>,
+) -> Result<()> {
+    record_stream_transport(&transport_stats, "audio", "inbound", "open", &stream);
+    let request: AudioRequest = serde_json::from_slice(&read_line(&mut stream.recv).await?)?;
+    tracing::info!(
+        peer = %stream.peer_id,
+        item = %request.item_id,
+        offset = request.offset,
+        "federation peer requested audio"
+    );
+
+    let track_id = match hex_decode_item_id(&request.item_id) {
+        Some(item_id) => match resolve_track_id(&pool, &own, item_id).await {
+            Ok(Some(track_id)) => track_id,
+            Ok(None) => return refuse_audio(stream, "track not found in the library").await,
+            Err(err) => {
+                return refuse_audio(stream, &format!("library lookup failed: {err:#}")).await;
+            }
+        },
+        None => return refuse_audio(stream, "malformed item_id").await,
+    };
+
+    let Some((file_path, mime_type)) = track_audio_file(&pool, track_id).await? else {
+        return refuse_audio(stream, "audio file record is missing").await;
+    };
+    let path = resolve_media_path(&storage_dir, &file_path);
+    let mut file = match tokio::fs::File::open(&path).await {
+        Ok(file) => file,
+        Err(err) => {
+            return refuse_audio(stream, &format!("audio file is not readable: {err}")).await;
+        }
+    };
+    let total_size = file.metadata().await?.len();
+    let offset = request.offset.min(total_size);
+    if offset > 0 {
+        file.seek(std::io::SeekFrom::Start(offset)).await?;
+    }
+
+    let metadata = match track_metadata(&pool, track_id).await {
+        Ok(metadata) => metadata,
+        Err(err) => {
+            tracing::warn!(track_id, "federation metadata lookup failed: {err:#}");
+            None
+        }
+    };
+    let (cover, artist_image) = if request.want_cover {
+        (
+            read_image(
+                &storage_dir,
+                track_cover_file(&pool, track_id).await.ok().flatten(),
+            )
+            .await,
+            read_image(
+                &storage_dir,
+                track_artist_image_file(&pool, track_id)
+                    .await
+                    .ok()
+                    .flatten(),
+            )
+            .await,
+        )
+    } else {
+        (None, None)
+    };
+
+    let mime_type = if mime_type.trim().is_empty() {
+        guess_mime(&path).to_string()
+    } else {
+        mime_type
+    };
+    write_line(
+        &mut stream.send,
+        &AudioResponseHeader {
+            ok: true,
+            error: None,
+            mime_type,
+            total_size,
+            offset,
+            metadata,
+            cover_size: cover.as_ref().map_or(0, |(bytes, _)| bytes.len() as u64),
+            cover_mime: cover
+                .as_ref()
+                .map(|(_, mime)| mime.clone())
+                .unwrap_or_default(),
+            artist_image_size: artist_image
+                .as_ref()
+                .map_or(0, |(bytes, _)| bytes.len() as u64),
+            artist_image_mime: artist_image
+                .as_ref()
+                .map(|(_, mime)| mime.clone())
+                .unwrap_or_default(),
+        },
+    )
+    .await?;
+    if let Some((bytes, _)) = &cover {
+        stream.send.write_all(bytes).await?;
+    }
+    if let Some((bytes, _)) = &artist_image {
+        stream.send.write_all(bytes).await?;
+    }
+    tokio::io::copy(&mut file, &mut stream.send).await?;
+    stream.send.finish()?;
+    // Wait until the peer read everything before dropping the stream,
+    // otherwise the tail of the file is lost.
+    let _ = stream.send.stopped().await;
+    record_stream_transport(&transport_stats, "audio", "inbound", "done", &stream);
+    Ok(())
+}
+
+async fn refuse_audio(mut stream: ByteStream, message: &str) -> Result<()> {
+    write_line(
+        &mut stream.send,
+        &AudioResponseHeader {
+            ok: false,
+            error: Some(message.to_string()),
+            ..AudioResponseHeader::default()
+        },
+    )
+    .await?;
+    stream.send.finish()?;
+    let _ = stream.send.stopped().await;
+    anyhow::bail!("refused audio request: {message}");
+}
+
+// ---------------------------------------------------------------------------
+// Catalog protocol
+// ---------------------------------------------------------------------------
+
+/// Runs the catalog accept loop until the acceptor closes.
+pub async fn serve_catalog(
+    mut acceptor: StreamAcceptor,
+    pool: PgPool,
+    storage_dir: String,
+    own: EndpointId,
+    transport_stats: Arc<TransportStats>,
+) {
+    while let Some(stream) = acceptor.accept().await {
+        let pool = pool.clone();
+        let storage_dir = storage_dir.clone();
+        let transport_stats = Arc::clone(&transport_stats);
+        tokio::spawn(async move {
+            let peer = stream.peer_id;
+            if let Err(err) =
+                serve_catalog_one(stream, pool, storage_dir, own, transport_stats).await
+            {
+                tracing::warn!(peer = %peer, "federation catalog request failed: {err:#}");
+            }
+        });
+    }
+}
+
+async fn serve_catalog_one(
+    mut stream: ByteStream,
+    pool: PgPool,
+    storage_dir: String,
+    own: EndpointId,
+    transport_stats: Arc<TransportStats>,
+) -> Result<()> {
+    record_stream_transport(&transport_stats, "catalog", "inbound", "open", &stream);
+    let request: CatalogRequest = serde_json::from_slice(&read_line(&mut stream.recv).await?)?;
+    tracing::info!(
+        peer = %stream.peer_id,
+        artist = %request.artist,
+        want = request.want.as_deref().unwrap_or("catalog"),
+        "federation peer requested a catalog"
+    );
+
+    match request.want.as_deref() {
+        None | Some("catalog") => {
+            let response = match build_catalog(&pool, &own, &request.artist).await {
+                Ok(response) => response,
+                Err(err) => CatalogResponse {
+                    ok: false,
+                    error: Some(format!("catalog lookup failed: {err:#}")),
+                    ..CatalogResponse::default()
+                },
+            };
+            stream
+                .send
+                .write_all(&serde_json::to_vec(&response)?)
+                .await?;
+        }
+        Some("artists") => {
+            let cursor = request.cursor.clone();
+            let limit = request.limit.unwrap_or(64).clamp(1, 200);
+            let response = match build_artist_slice(&pool, cursor, limit).await {
+                Ok(response) => response,
+                Err(err) => CatalogResponse {
+                    ok: false,
+                    error: Some(format!("artist slice lookup failed: {err:#}")),
+                    ..CatalogResponse::default()
+                },
+            };
+            stream
+                .send
+                .write_all(&serde_json::to_vec(&response)?)
+                .await?;
+        }
+        Some(want @ ("artist_image" | "release_cover")) => {
+            let media = if want == "release_cover" {
+                release_cover_by_names(
+                    &pool,
+                    &request.artist,
+                    request.release.as_deref().unwrap_or_default(),
+                )
+                .await?
+            } else {
+                artist_image_by_name(&pool, &request.artist).await?
+            };
+            let image = read_image(&storage_dir, media).await;
+            let header = match &image {
+                Some((bytes, mime)) => ImageHeader {
+                    ok: true,
+                    error: None,
+                    mime_type: mime.clone(),
+                    size: bytes.len() as u64,
+                },
+                None => ImageHeader {
+                    ok: false,
+                    error: Some("no image".to_string()),
+                    ..ImageHeader::default()
+                },
+            };
+            write_line(&mut stream.send, &header).await?;
+            if let Some((bytes, _)) = &image {
+                stream.send.write_all(bytes).await?;
+            }
+        }
+        Some(other) => {
+            let response = CatalogResponse {
+                ok: false,
+                error: Some(format!("unknown request kind '{other}'")),
+                ..CatalogResponse::default()
+            };
+            stream
+                .send
+                .write_all(&serde_json::to_vec(&response)?)
+                .await?;
+        }
+    }
+    stream.send.finish()?;
+    let _ = stream.send.stopped().await;
+    record_stream_transport(&transport_stats, "catalog", "inbound", "done", &stream);
+    Ok(())
+}
+
+async fn build_catalog(pool: &PgPool, own: &EndpointId, artist: &str) -> Result<CatalogResponse> {
+    let Some(artist_row) = sqlx::query(
+        "SELECT id, name FROM furumusic__artist
+         WHERE LOWER(name) = LOWER($1) AND is_hidden = false
+         LIMIT 1",
+    )
+    .bind(artist)
+    .fetch_optional(pool)
+    .await?
+    else {
+        return Ok(CatalogResponse {
+            ok: false,
+            error: Some("artist not found in the library".to_string()),
+            ..CatalogResponse::default()
+        });
+    };
+    let artist_id: i64 = artist_row.get(0);
+
+    let release_rows = sqlx::query(
+        "SELECT r.id, r.title, r.release_type, r.year
+         FROM furumusic__release r
+         JOIN furumusic__release_artist ra ON ra.release_id = r.id
+         WHERE ra.artist_id = $1 AND r.is_hidden = false
+         ORDER BY r.year NULLS LAST, r.title",
+    )
+    .bind(artist_id)
+    .fetch_all(pool)
+    .await?;
+    let mut releases = Vec::new();
+    for release_row in release_rows {
+        let release_id: i64 = release_row.get(0);
+        let track_rows = sqlx::query(
+            "SELECT t.id, t.title, t.track_number, t.disc_number, t.duration_seconds,
+                    c.content_id
+             FROM furumusic__track t
+             JOIN furumusic__media_file m ON m.id = t.audio_file_id
+             LEFT JOIN furumusic__federation_content_id_cache c
+                    ON c.media_file_id = m.id AND c.sha256_hash = m.sha256_hash
+             WHERE t.release_id = $1 AND t.is_hidden = false
+             ORDER BY t.disc_number NULLS FIRST, t.track_number NULLS LAST, t.title",
+        )
+        .bind(release_id)
+        .fetch_all(pool)
+        .await?;
+        let mut tracks = Vec::with_capacity(track_rows.len());
+        for row in track_rows {
+            let track_id: i64 = row.get(0);
+            let duration: f64 = row.get(4);
+            let (artists, featured_artists) = track_catalog_artist_names(pool, track_id).await?;
+            tracks.push(CatalogTrack {
+                title: row.get(1),
+                artists,
+                featured_artists,
+                track_number: row.get(2),
+                disc_number: row.get(3),
+                duration_seconds: (duration > 0.0).then_some(duration),
+                content_id: row.get(5),
+                item_id: item_id_of(own, track_id),
+            });
+        }
+        releases.push(CatalogRelease {
+            title: release_row.get(1),
+            release_type: release_row.get(2),
+            year: release_row.get(3),
+            tracks,
+        });
+    }
+
+    Ok(CatalogResponse {
+        ok: true,
+        artist: Some(CatalogArtist {
+            name: artist_row.get(1),
+            releases,
+            appears_on: Vec::new(),
+        }),
+        ..CatalogResponse::default()
+    })
+}
+
+async fn build_artist_slice(
+    pool: &PgPool,
+    cursor: Option<String>,
+    limit: usize,
+) -> Result<CatalogResponse> {
+    let offset = cursor
+        .as_deref()
+        .and_then(|value| value.parse::<i64>().ok())
+        .unwrap_or(0)
+        .max(0);
+    let rows = sqlx::query(
+        r#"SELECT a.name::text AS name,
+                  mf.file_path::text AS image_path,
+                  COALESCE(s.release_count, 0)::bigint AS release_count,
+                  COALESCE(s.track_count, 0)::bigint AS track_count
+           FROM furumusic__artist a
+           LEFT JOIN furumusic__media_file mf ON mf.id = a.image_file_id
+           LEFT JOIN (
+               SELECT appearance.artist_id,
+                      COUNT(DISTINCT appearance.release_id) FILTER (WHERE appearance.is_primary_release_artist) AS release_count,
+                      COUNT(DISTINCT appearance.track_id) AS track_count
+                 FROM (
+                        SELECT ta.artist_id,
+                               t.id AS track_id,
+                               r.id AS release_id,
+                               primary_release.artist_id IS NOT NULL AS is_primary_release_artist
+                          FROM furumusic__track_artist ta
+                          JOIN furumusic__track t ON t.id = ta.track_id AND t.is_hidden = false
+                          JOIN furumusic__release r ON r.id = t.release_id AND r.is_hidden = false
+                          LEFT JOIN furumusic__release_artist primary_release
+                            ON primary_release.release_id = r.id
+                           AND primary_release.artist_id = ta.artist_id
+                           AND primary_release.position = 0
+                      ) appearance
+                GROUP BY appearance.artist_id
+           ) s ON s.artist_id = a.id
+           WHERE a.is_hidden = false
+             AND COALESCE(s.track_count, 0) > 0
+           ORDER BY (COALESCE(s.release_count, 0) > 0) DESC,
+                    COALESCE(s.release_count, 0) DESC,
+                    COALESCE(s.track_count, 0) DESC,
+                    a.name_sort
+           LIMIT $1 OFFSET $2"#,
+    )
+    .bind(limit as i64 + 1)
+    .bind(offset)
+    .fetch_all(pool)
+    .await?;
+
+    let mut artists = Vec::with_capacity(rows.len().min(limit));
+    let has_more = rows.len() > limit;
+    for row in rows.into_iter().take(limit) {
+        let name: String = row.get(0);
+        artists.push(CatalogArtistPreview {
+            artist_key: normalize_name(&name),
+            name,
+            image_path: row.get(1),
+            release_count: row.get(2),
+            track_count: row.get(3),
+        });
+    }
+    let next_cursor = has_more.then(|| (offset + artists.len() as i64).to_string());
+    Ok(CatalogResponse {
+        ok: true,
+        artists,
+        next_cursor,
+        ..CatalogResponse::default()
+    })
+}
+
+async fn artist_image_by_name(pool: &PgPool, artist: &str) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__artist a
+         JOIN furumusic__media_file m ON m.id = a.image_file_id
+         WHERE LOWER(a.name) = LOWER($1) AND a.is_hidden = false
+         LIMIT 1",
+    )
+    .bind(artist)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}
+
+async fn release_cover_by_names(
+    pool: &PgPool,
+    artist: &str,
+    release: &str,
+) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__release r
+         JOIN furumusic__release_artist ra ON ra.release_id = r.id
+         JOIN furumusic__artist a ON a.id = ra.artist_id
+         JOIN furumusic__media_file m ON m.id = r.cover_file_id
+         WHERE LOWER(a.name) = LOWER($1) AND LOWER(r.title) = LOWER($2)
+         LIMIT 1",
+    )
+    .bind(artist)
+    .bind(release)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}

src/federation/storage.rs

@@ -0,0 +1,349 @@
+use std::str::FromStr;
+
+use async_trait::async_trait;
+use music_dht::{
+    DhtKey, EndpointId, LibraryItem, MAX_RECORDS_PER_RESPONSE, MusicDhtError, MusicDhtStorage,
+    NodeContact, NodeId, SecretKey, StoreDecision, StoredRecord, decide_store,
+};
+use sqlx::{PgPool, Row as _};
+
+const IDENTITY_NAME: &str = "default";
+
+const SCHEMA: &[&str] = &[
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_identity (
+        name        TEXT PRIMARY KEY,
+        secret_key  BYTEA NOT NULL,
+        created_at  TEXT NOT NULL,
+        updated_at  TEXT NOT NULL
+    )",
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_local_item (
+        id              BYTEA PRIMARY KEY,
+        normalized_name TEXT NOT NULL,
+        revision        BIGINT NOT NULL,
+        deleted         BOOLEAN NOT NULL DEFAULT false,
+        updated_at_ms   BIGINT NOT NULL,
+        payload         BYTEA NOT NULL
+    )",
+    "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_local_item_normalized_name
+        ON furumusic__federation_local_item(normalized_name)",
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_dht_record (
+        dht_key          BYTEA NOT NULL,
+        item_id          BYTEA NOT NULL,
+        owner_peer_id    TEXT NOT NULL,
+        payload          BYTEA NOT NULL,
+        revision         BIGINT NOT NULL,
+        deleted          BOOLEAN NOT NULL,
+        expires_at_ms    BIGINT NOT NULL,
+        PRIMARY KEY (dht_key, item_id, owner_peer_id)
+    )",
+    "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_dht_record_expires_at
+        ON furumusic__federation_dht_record(expires_at_ms)",
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_known_peer (
+        peer_id       TEXT PRIMARY KEY,
+        node_id       BYTEA NOT NULL,
+        ticket        TEXT NOT NULL,
+        last_seen_ms  BIGINT NOT NULL
+    )",
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_content_id_cache (
+        media_file_id  BIGINT PRIMARY KEY,
+        sha256_hash    TEXT NOT NULL,
+        content_id     TEXT NOT NULL,
+        updated_at     TEXT NOT NULL
+    )",
+    "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_content_id_cache_content_id
+        ON furumusic__federation_content_id_cache(content_id)",
+];
+
+#[derive(Debug, Clone)]
+pub struct PostgresFederationStorage {
+    pool: PgPool,
+}
+
+impl PostgresFederationStorage {
+    pub async fn new(pool: PgPool) -> music_dht::Result<Self> {
+        let storage = Self { pool };
+        storage.ensure_schema().await?;
+        Ok(storage)
+    }
+
+    pub async fn load_or_create_secret_key(&self) -> music_dht::Result<SecretKey> {
+        if let Some(bytes) = sqlx::query_scalar::<_, Vec<u8>>(
+            "SELECT secret_key FROM furumusic__federation_identity WHERE name = $1",
+        )
+        .bind(IDENTITY_NAME)
+        .fetch_optional(&self.pool)
+        .await
+        .map_err(db_error)?
+        {
+            return secret_from_bytes(bytes);
+        }
+
+        let key = SecretKey::generate();
+        let key_bytes = key.to_bytes();
+        let now = now_iso();
+        let inserted = sqlx::query(
+            "INSERT INTO furumusic__federation_identity
+             (name, secret_key, created_at, updated_at)
+             VALUES ($1, $2, $3, $4)
+             ON CONFLICT (name) DO NOTHING",
+        )
+        .bind(IDENTITY_NAME)
+        .bind(key_bytes.as_slice())
+        .bind(&now)
+        .bind(&now)
+        .execute(&self.pool)
+        .await
+        .map_err(db_error)?
+        .rows_affected();
+        if inserted == 1 {
+            return Ok(key);
+        }
+
+        let bytes = sqlx::query_scalar::<_, Vec<u8>>(
+            "SELECT secret_key FROM furumusic__federation_identity WHERE name = $1",
+        )
+        .bind(IDENTITY_NAME)
+        .fetch_one(&self.pool)
+        .await
+        .map_err(db_error)?;
+        secret_from_bytes(bytes)
+    }
+
+    async fn ensure_schema(&self) -> music_dht::Result<()> {
+        for sql in SCHEMA {
+            sqlx::query(sql)
+                .execute(&self.pool)
+                .await
+                .map_err(db_error)?;
+        }
+        Ok(())
+    }
+}
+
+#[async_trait]
+impl MusicDhtStorage for PostgresFederationStorage {
+    async fn upsert_local_item(&self, item: &LibraryItem) -> music_dht::Result<()> {
+        let payload = postcard::to_stdvec(item).map_err(db_error)?;
+        sqlx::query(
+            "INSERT INTO furumusic__federation_local_item
+             (id, normalized_name, revision, deleted, updated_at_ms, payload)
+             VALUES ($1, $2, $3, $4, $5, $6)
+             ON CONFLICT (id) DO UPDATE SET
+                normalized_name = EXCLUDED.normalized_name,
+                revision = EXCLUDED.revision,
+                deleted = EXCLUDED.deleted,
+                updated_at_ms = EXCLUDED.updated_at_ms,
+                payload = EXCLUDED.payload",
+        )
+        .bind(item.id.as_bytes().as_slice())
+        .bind(&item.normalized_name)
+        .bind(item.revision as i64)
+        .bind(item.deleted)
+        .bind(item.updated_at_ms as i64)
+        .bind(payload)
+        .execute(&self.pool)
+        .await
+        .map_err(db_error)?;
+        Ok(())
+    }
+
+    async fn list_local_items(&self, include_deleted: bool) -> music_dht::Result<Vec<LibraryItem>> {
+        let rows = sqlx::query(
+            "SELECT payload
+             FROM furumusic__federation_local_item
+             WHERE $1 OR deleted = false
+             ORDER BY normalized_name",
+        )
+        .bind(include_deleted)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(db_error)?;
+        Ok(rows
+            .into_iter()
+            .filter_map(|row| postcard::from_bytes::<LibraryItem>(&row.get::<Vec<u8>, _>(0)).ok())
+            .collect())
+    }
+
+    async fn store_dht_record(&self, key: DhtKey, record: StoredRecord) -> music_dht::Result<bool> {
+        let mut conn = self.pool.acquire().await.map_err(db_error)?;
+        store_record_in_conn(&mut conn, &key, &record).await
+    }
+
+    async fn store_dht_records(
+        &self,
+        entries: Vec<(DhtKey, StoredRecord)>,
+    ) -> music_dht::Result<Vec<bool>> {
+        let mut tx = self.pool.begin().await.map_err(db_error)?;
+        let mut stored = Vec::with_capacity(entries.len());
+        for (key, record) in &entries {
+            stored.push(store_record_in_conn(&mut tx, key, record).await?);
+        }
+        tx.commit().await.map_err(db_error)?;
+        Ok(stored)
+    }
+
+    async fn dht_records_by_key(
+        &self,
+        key: DhtKey,
+        now_ms: u64,
+    ) -> music_dht::Result<Vec<StoredRecord>> {
+        let rows = sqlx::query(
+            "SELECT payload
+             FROM furumusic__federation_dht_record
+             WHERE dht_key = $1 AND expires_at_ms > $2
+             ORDER BY expires_at_ms DESC, item_id
+             LIMIT $3",
+        )
+        .bind(key.as_bytes().as_slice())
+        .bind(now_ms as i64)
+        .bind(MAX_RECORDS_PER_RESPONSE as i64)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(db_error)?;
+        Ok(rows
+            .into_iter()
+            .filter_map(|row| postcard::from_bytes::<StoredRecord>(&row.get::<Vec<u8>, _>(0)).ok())
+            .collect())
+    }
+
+    async fn delete_expired_records(&self, now_ms: u64) -> music_dht::Result<usize> {
+        let result =
+            sqlx::query("DELETE FROM furumusic__federation_dht_record WHERE expires_at_ms <= $1")
+                .bind(now_ms as i64)
+                .execute(&self.pool)
+                .await
+                .map_err(db_error)?;
+        Ok(result.rows_affected() as usize)
+    }
+
+    async fn upsert_known_peer(&self, contact: &NodeContact) -> music_dht::Result<()> {
+        sqlx::query(
+            "INSERT INTO furumusic__federation_known_peer
+             (peer_id, node_id, ticket, last_seen_ms)
+             VALUES ($1, $2, $3, $4)
+             ON CONFLICT (peer_id) DO UPDATE SET
+                node_id = EXCLUDED.node_id,
+                ticket = EXCLUDED.ticket,
+                last_seen_ms = EXCLUDED.last_seen_ms",
+        )
+        .bind(contact.peer_id.to_string())
+        .bind(contact.node_id.as_bytes().as_slice())
+        .bind(&contact.ticket)
+        .bind(contact.last_seen_ms as i64)
+        .execute(&self.pool)
+        .await
+        .map_err(db_error)?;
+        Ok(())
+    }
+
+    async fn delete_known_peer(&self, peer_id: EndpointId) -> music_dht::Result<()> {
+        sqlx::query("DELETE FROM furumusic__federation_known_peer WHERE peer_id = $1")
+            .bind(peer_id.to_string())
+            .execute(&self.pool)
+            .await
+            .map_err(db_error)?;
+        Ok(())
+    }
+
+    async fn load_known_peers(&self) -> music_dht::Result<Vec<NodeContact>> {
+        let rows = sqlx::query(
+            "SELECT peer_id, node_id, ticket, last_seen_ms
+             FROM furumusic__federation_known_peer",
+        )
+        .fetch_all(&self.pool)
+        .await
+        .map_err(db_error)?;
+        let mut contacts = Vec::new();
+        for row in rows {
+            let peer_id: String = row.get(0);
+            let node_id: Vec<u8> = row.get(1);
+            let ticket: String = row.get(2);
+            let last_seen_ms: i64 = row.get(3);
+            let Ok(peer_id) = EndpointId::from_str(&peer_id) else {
+                continue;
+            };
+            let Ok(node_id) = <[u8; 32]>::try_from(node_id.as_slice()) else {
+                continue;
+            };
+            contacts.push(NodeContact {
+                node_id: NodeId::from_bytes(node_id),
+                peer_id,
+                ticket,
+                last_seen_ms: last_seen_ms as u64,
+            });
+        }
+        Ok(contacts)
+    }
+}
+
+fn now_iso() -> String {
+    chrono::Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string()
+}
+
+fn secret_from_bytes(bytes: Vec<u8>) -> music_dht::Result<SecretKey> {
+    let bytes: [u8; 32] = bytes
+        .as_slice()
+        .try_into()
+        .map_err(|_| MusicDhtError::Database("stored federation identity is corrupted".into()))?;
+    Ok(SecretKey::from_bytes(&bytes))
+}
+
+/// Applies one validated record following the revision/tombstone rules.
+/// Returns `true` if the record was written or refreshed. Runs against a
+/// pooled connection or an open transaction.
+async fn store_record_in_conn(
+    conn: &mut sqlx::PgConnection,
+    key: &DhtKey,
+    record: &StoredRecord,
+) -> music_dht::Result<bool> {
+    let existing = sqlx::query(
+        "SELECT revision, deleted, expires_at_ms
+         FROM furumusic__federation_dht_record
+         WHERE dht_key = $1 AND item_id = $2 AND owner_peer_id = $3",
+    )
+    .bind(key.as_bytes().as_slice())
+    .bind(record.item.id.as_bytes().as_slice())
+    .bind(record.item.owner.to_string())
+    .fetch_optional(&mut *conn)
+    .await
+    .map_err(db_error)?
+    .map(|row| {
+        (
+            row.get::<i64, _>(0) as u64,
+            row.get::<bool, _>(1),
+            row.get::<i64, _>(2) as u64,
+        )
+    });
+
+    match decide_store(existing, record) {
+        StoreDecision::Ignore => return Ok(false),
+        StoreDecision::Write | StoreDecision::RefreshExpiry(_) => {}
+    }
+
+    let payload = postcard::to_stdvec(record).map_err(db_error)?;
+    sqlx::query(
+        "INSERT INTO furumusic__federation_dht_record
+         (dht_key, item_id, owner_peer_id, payload, revision, deleted, expires_at_ms)
+         VALUES ($1, $2, $3, $4, $5, $6, $7)
+         ON CONFLICT (dht_key, item_id, owner_peer_id) DO UPDATE SET
+            payload = EXCLUDED.payload,
+            revision = EXCLUDED.revision,
+            deleted = EXCLUDED.deleted,
+            expires_at_ms = EXCLUDED.expires_at_ms",
+    )
+    .bind(key.as_bytes().as_slice())
+    .bind(record.item.id.as_bytes().as_slice())
+    .bind(record.item.owner.to_string())
+    .bind(payload)
+    .bind(record.item.revision as i64)
+    .bind(record.item.deleted)
+    .bind(record.expires_at_ms as i64)
+    .execute(&mut *conn)
+    .await
+    .map_err(db_error)?;
+    Ok(true)
+}
+
+fn db_error(err: impl std::fmt::Display) -> MusicDhtError {
+    MusicDhtError::Database(err.to_string())
+}

src/i18n/phrases.rs

@@ -272,6 +272,8 @@ translations! {
     // Player UI
     player_library:          "Library"                         , "Библиотека";
     player_artists:          "Artists"                         , "Артисты";
+    player_global_library:   "Global"                          , "Global";
+    player_featured_only_artists: "Featured only"               , "Только фиты";
     player_release:          "Release"                         , "Релиз";
     player_releases:         "Releases"                        , "Релизы";
     player_tracks:           "Tracks"                          , "Треки";
@@ -298,6 +300,7 @@ translations! {
     player_search_placeholder: "Search artists, releases, tracks..." , "Поиск артистов, релизов, треков...";
     player_connection_lost: "Server connection lost"             , "Нет соединения с сервером";
     player_connection_lost_detail: "Player cannot reach the server. Retrying..." , "Плеер не может связаться с сервером. Повторяю...";
+    player_active_device:   "Active device"                   , "Активный девайс";
     player_no_results:       "No results found"                , "Ничего не найдено";
     player_new_playlist:     "New Playlist"                    , "Новый плейлист";
     player_rename_playlist:  "Rename Playlist"                 , "Переименовать плейлист";
@@ -306,6 +309,7 @@ translations! {
     player_cancel:           "Cancel"                          , "Отмена";
     player_create:           "Create"                          , "Создать";
     player_save:             "Save"                            , "Сохранить";
+    player_done:             "Done"                            , "Готово";
     player_delete:           "Delete"                          , "Удалить";
     player_delete_playlist_confirm: "Delete this playlist?"     , "Удалить этот плейлист?";
     player_rename:           "Rename"                          , "Переименовать";
@@ -355,6 +359,11 @@ translations! {
     player_add_to_queue:     "Add to queue"                    , "Добавить в очередь";
     player_add_to_end_queue: "Add to end of queue"             , "Добавить в конец очереди";
     player_play_next:        "Play next"                       , "Играть следующим";
+    player_share:            "Share"                           , "Поделиться";
+    player_share_track:      "Share track"                     , "Поделиться треком";
+    player_share_queue:      "Share queue"                     , "Поделиться очередью";
+    player_shared_playlist:  "Shared playlist"                 , "Общий плейлист";
+    player_jam_play_on_this_device: "Play on this device"      , "Играть на этом устройстве";
     player_queue:            "Queue"                           , "Очередь";
     player_next:             "Next"                            , "Далее";
     player_previous:         "Previous"                        , "Назад";
@@ -365,6 +374,7 @@ translations! {
     player_repeat:           "Repeat"                          , "Повтор";
     player_volume:           "Volume"                          , "Громкость";
     player_appears_on:       "Appears on"                      , "Участвует в";
+    player_top_tracks:       "Popular tracks"                  , "Популярные треки";
     player_albums:           "Albums"                          , "Альбомы";
     player_eps:              "EPs"                             , "EP";
     player_singles:          "Singles"                         , "Синглы";
@@ -386,7 +396,71 @@ translations! {
     player_saved_torrents:   "Saved torrents"                  , "Сохранённые торренты";
     player_refresh:          "Refresh"                         , "Обновить";
     player_no_saved_torrents: "No saved torrents"              , "Сохранённых торрентов нет";
+    player_import:           "Import"                          , "Импорт";
     player_upload:           "Upload"                          , "Загрузить";
+    player_my_uploads:       "My uploads"                      , "Мои загрузки";
+    player_my_uploaded_tracks: "My uploaded tracks"             , "Мои загруженные треки";
+    player_no_uploaded_tracks: "No uploaded tracks yet"         , "Загруженных треков пока нет";
+    player_needs_approval:   "Needs approval"                  , "Нужно подтверждение";
+    player_pending_or_failed: "pending or failed"               , "ожидают или с ошибкой";
+    player_no_tracks_need_approval: "No tracks need approval"   , "Нет треков для подтверждения";
+    player_queued_processing: "Queued / processing"             , "В очереди / обработке";
+    player_showing:          "Showing"                         , "Показано";
+    player_status:           "Status"                          , "Статус";
+    player_file:             "File"                            , "Файл";
+    player_created:          "Created"                         , "Создано";
+    player_updated:          "Updated"                         , "Обновлено";
+    player_error:            "Error"                           , "Ошибка";
+    player_pending:          "Pending"                         , "Ожидает";
+    player_artist:           "Artist"                          , "Артист";
+    player_album:            "Album"                           , "Альбом";
+    player_album_artists:    "Album artists"                   , "Артисты альбома";
+    player_featured:         "Featured"                        , "При участии";
+    player_featured_short:   "feat."                           , "уч.";
+    player_track_number:     "Track #"                         , "Трек #";
+    player_disc_number:      "Disc #"                          , "Диск #";
+    player_genre:            "Genre"                           , "Жанр";
+    player_notes:            "Notes"                           , "Заметки";
+    player_type_unchanged:   "Type unchanged"                  , "Тип без изменений";
+    player_visibility_unchanged: "Visibility unchanged"         , "Видимость без изменений";
+    player_visible:          "Visible"                         , "Видимый";
+    player_hidden:           "Hidden"                          , "Скрыт";
+    player_no_year:          "no year"                         , "год неизвестен";
+    player_apply:            "Apply"                           , "Применить";
+    player_edit:             "Edit"                            , "Редактировать";
+    player_edit_release:     "Edit release"                    , "Редактировать релиз";
+    player_edit_track:       "Edit track"                      , "Редактировать трек";
+    player_edit_metadata:    "Edit metadata"                   , "Редактировать метаданные";
+    player_metadata:         "Metadata"                        , "Метаданные";
+    player_release_metadata: "Release metadata"                , "Метаданные релиза";
+    player_track_metadata:   "Track metadata"                  , "Метаданные трека";
+    player_approve_metadata: "Approve metadata"                , "Подтвердить метаданные";
+    player_delete_review:    "Delete review"                   , "Удалить проверку";
+    player_approve:          "Approve"                         , "Подтвердить";
+    player_save_track:       "Save track"                      , "Сохранить трек";
+    player_save_release:     "Save release"                    , "Сохранить релиз";
+    player_artists_placeholder: "Artist, Artist"               , "Артист, артист";
+    player_artist_featured_placeholder: "Artist, Featured Artist" , "Артист, приглашённый артист";
+    player_release_type_album: "Album"                         , "Альбом";
+    player_release_type_single: "Single"                       , "Сингл";
+    player_release_type_ep:  "EP"                              , "EP";
+    player_release_type_compilation: "Compilation"             , "Сборник";
+    player_release_type_mixtape: "Mixtape"                     , "Микстейп";
+    player_release_type_live: "Live"                           , "Концерт";
+    player_release_type_soundtrack: "Soundtrack"               , "Саундтрек";
+    player_release_type_remix: "Remix"                         , "Ремикс";
+    player_release_type_demo: "Demo"                           , "Демо";
+    player_failed_load_uploaded_tracks: "Failed to load uploaded tracks" , "Не удалось загрузить загруженные треки";
+    player_failed_save_track: "Failed to save track"           , "Не удалось сохранить трек";
+    player_track_metadata_saved: "Track metadata saved"         , "Метаданные трека сохранены";
+    player_failed_save_release: "Failed to save release"       , "Не удалось сохранить релиз";
+    player_release_metadata_saved: "Release metadata saved"     , "Метаданные релиза сохранены";
+    player_failed_delete_review: "Failed to delete review"     , "Не удалось удалить проверку";
+    player_review_deleted:   "Review deleted"                  , "Проверка удалена";
+    player_failed_approve_review: "Failed to approve review"   , "Не удалось подтвердить проверку";
+    player_track_approved_imported: "Track approved and imported" , "Трек подтверждён и импортирован";
+    player_failed_update_selected_tracks: "Failed to update selected tracks" , "Не удалось обновить выбранные треки";
+    player_selected_tracks_updated: "Selected tracks updated"   , "Выбранные треки обновлены";
     player_choose_saved_or_add_torrent: "Choose a saved item or upload new files." , "Выберите сохранённый элемент или загрузите новые файлы.";
     player_local_files:      "Local audio files"               , "Локальные аудиофайлы";
     player_torrent_file:     "Torrent file"                    , "Torrent-файл";
@@ -414,6 +488,7 @@ translations! {
     player_seen:             "seen"                            , "видели";
     player_eta:              "eta"                             , "осталось";
     player_loading_history:  "Loading history..."              , "Загрузка истории...";
+    player_loading_more:     "Loading more..."                 , "Загружаю ещё...";
     player_failed_load_history: "Failed to load history"        , "Не удалось загрузить историю";
     player_total_plays:      "total plays"                     , "прослушиваний всего";
     player_play_history:     "Play history"                    , "История прослушиваний";

src/jobs/archive_cleanup.rs

@@ -0,0 +1,431 @@
+use std::collections::BTreeSet;
+use std::io::ErrorKind;
+
+use sqlx::PgPool;
+
+use crate::scheduler::{Job, JobContext, JobLog};
+
+const SAMPLE_LOG_LIMIT: usize = 50;
+
+pub struct ArchiveCleanupJob;
+
+#[derive(Debug, sqlx::FromRow)]
+struct TrackFileRow {
+    track_id: i64,
+    track_title: String,
+    release_id: i64,
+    release_title: Option<String>,
+    media_file_id: Option<i64>,
+    file_type: Option<String>,
+    file_path: Option<String>,
+}
+
+#[derive(Debug)]
+struct MissingTrack {
+    track_id: i64,
+    track_title: String,
+    release_id: i64,
+    release_title: Option<String>,
+    media_file_id: Option<i64>,
+    file_path: Option<String>,
+    reason: MissingReason,
+}
+
+#[derive(Debug)]
+enum MissingReason {
+    MissingMediaRow,
+    InvalidMediaType(String),
+    EmptyPath,
+    MissingFile,
+    NotRegularFile,
+}
+
+#[derive(Debug, Default)]
+struct DeleteStats {
+    playback_states_cleared: u64,
+    playlist_entries_deleted: u64,
+    likes_deleted: u64,
+    play_history_deleted: u64,
+    popularity_history_deleted: u64,
+    scrobble_outbox_deleted: u64,
+    track_genres_deleted: u64,
+    entity_tags_deleted: u64,
+    external_ids_deleted: u64,
+    track_artists_deleted: u64,
+    tracks_deleted: u64,
+    media_files_deleted: u64,
+}
+
+#[async_trait::async_trait]
+impl Job for ArchiveCleanupJob {
+    fn name(&self) -> &'static str {
+        "archive_cleanup"
+    }
+
+    fn description(&self) -> &'static str {
+        "Clean stale archive records, starting with tracks whose audio files are missing"
+    }
+
+    fn default_cron(&self) -> &'static str {
+        // Daily at 04:45.
+        "0 45 4 * * *"
+    }
+
+    async fn run(&self, ctx: &JobContext, log: &mut JobLog) -> anyhow::Result<()> {
+        run_missing_audio_cleanup(ctx, log).await
+    }
+}
+
+async fn run_missing_audio_cleanup(ctx: &JobContext, log: &mut JobLog) -> anyhow::Result<()> {
+    let storage_dir = ctx.config.agent_storage_dir.trim();
+    if storage_dir.is_empty() {
+        log.warn("Archive cleanup: agent_storage_dir is not configured, skipping file checks");
+        return Ok(());
+    }
+
+    let rows = sqlx::query_as::<_, TrackFileRow>(
+        r#"SELECT t.id AS track_id,
+                  t.title::text AS track_title,
+                  t.release_id,
+                  r.title::text AS release_title,
+                  mf.id AS media_file_id,
+                  mf.file_type::text AS file_type,
+                  mf.file_path::text AS file_path
+             FROM furumusic__track t
+             LEFT JOIN furumusic__release r ON r.id = t.release_id
+             LEFT JOIN furumusic__media_file mf ON mf.id = t.audio_file_id
+            ORDER BY t.id"#,
+    )
+    .fetch_all(&ctx.pool)
+    .await?;
+
+    if rows.is_empty() {
+        log.info("Archive cleanup: no tracks found");
+        return Ok(());
+    }
+
+    log.info(&format!(
+        "Archive cleanup: checking {} track audio reference(s)",
+        rows.len()
+    ));
+
+    let mut missing_tracks = Vec::new();
+    let mut skipped_io_errors = 0u64;
+
+    for row in rows {
+        let Some(media_file_id) = row.media_file_id else {
+            missing_tracks.push(MissingTrack::from_row(row, MissingReason::MissingMediaRow));
+            continue;
+        };
+
+        let file_type = row.file_type.clone();
+        match file_type.as_deref() {
+            Some("audio") => {}
+            Some(file_type) => {
+                missing_tracks.push(MissingTrack::from_row(
+                    row,
+                    MissingReason::InvalidMediaType(file_type.to_owned()),
+                ));
+                continue;
+            }
+            None => {
+                missing_tracks.push(MissingTrack::from_row(row, MissingReason::MissingMediaRow));
+                continue;
+            }
+        }
+
+        let Some(file_path) = row
+            .file_path
+            .as_deref()
+            .map(str::trim)
+            .filter(|path| !path.is_empty())
+        else {
+            missing_tracks.push(MissingTrack::from_row(row, MissingReason::EmptyPath));
+            continue;
+        };
+
+        let absolute_path = crate::media_paths::resolve_media_file_path(storage_dir, file_path);
+        match tokio::fs::metadata(&absolute_path).await {
+            Ok(meta) if meta.is_file() => {}
+            Ok(_) => {
+                missing_tracks.push(MissingTrack::from_row(row, MissingReason::NotRegularFile));
+            }
+            Err(err) if err.kind() == ErrorKind::NotFound => {
+                missing_tracks.push(MissingTrack::from_row(row, MissingReason::MissingFile));
+            }
+            Err(err) => {
+                skipped_io_errors += 1;
+                log.warn(&format!(
+                    "Archive cleanup: skipping track {} media_file_id={media_file_id}; cannot inspect {}: {err}",
+                    row.track_id,
+                    absolute_path.display()
+                ));
+            }
+        }
+    }
+
+    if missing_tracks.is_empty() {
+        log.info(&format!(
+            "Archive cleanup: all checked tracks have readable audio files; skipped_io_errors={skipped_io_errors}"
+        ));
+        return Ok(());
+    }
+
+    for (index, track) in missing_tracks.iter().take(SAMPLE_LOG_LIMIT).enumerate() {
+        log.warn(&format!(
+            "Archive cleanup: deleting stale track {} \"{}\"{}{} ({})",
+            track.track_id,
+            track.track_title,
+            track
+                .release_title
+                .as_deref()
+                .map(|title| format!(" from \"{title}\""))
+                .unwrap_or_default(),
+            track
+                .file_path
+                .as_deref()
+                .map(|path| format!(", path={path}"))
+                .unwrap_or_default(),
+            track.reason
+        ));
+        if index + 1 == SAMPLE_LOG_LIMIT && missing_tracks.len() > SAMPLE_LOG_LIMIT {
+            log.warn(&format!(
+                "Archive cleanup: suppressing per-track logs for remaining {} stale track(s)",
+                missing_tracks.len() - SAMPLE_LOG_LIMIT
+            ));
+        }
+    }
+
+    let track_ids = unique_sorted(
+        missing_tracks
+            .iter()
+            .map(|track| track.track_id)
+            .collect::<Vec<_>>(),
+    );
+    let media_file_ids = unique_sorted(
+        missing_tracks
+            .iter()
+            .filter_map(|track| track.media_file_id)
+            .collect::<Vec<_>>(),
+    );
+    let release_ids = unique_sorted(
+        missing_tracks
+            .iter()
+            .map(|track| track.release_id)
+            .collect::<Vec<_>>(),
+    );
+
+    let stats =
+        delete_tracks_and_unreferenced_audio_media(&ctx.pool, &track_ids, &media_file_ids).await?;
+    let empty_release_count = count_empty_releases(&ctx.pool, &release_ids).await?;
+
+    log.info(&format!(
+        "Archive cleanup: deleted {} track(s), {} unreferenced audio media_file row(s); cleared playback_states={}, playlist_entries={}, likes={}, play_history={}, popularity_history={}, scrobble_outbox={}, track_genres={}, entity_tags={}, external_ids={}, track_artists={}; skipped_io_errors={skipped_io_errors}; empty_releases_left={empty_release_count}",
+        stats.tracks_deleted,
+        stats.media_files_deleted,
+        stats.playback_states_cleared,
+        stats.playlist_entries_deleted,
+        stats.likes_deleted,
+        stats.play_history_deleted,
+        stats.popularity_history_deleted,
+        stats.scrobble_outbox_deleted,
+        stats.track_genres_deleted,
+        stats.entity_tags_deleted,
+        stats.external_ids_deleted,
+        stats.track_artists_deleted,
+    ));
+
+    Ok(())
+}
+
+impl MissingTrack {
+    fn from_row(row: TrackFileRow, reason: MissingReason) -> Self {
+        Self {
+            track_id: row.track_id,
+            track_title: row.track_title,
+            release_id: row.release_id,
+            release_title: row.release_title,
+            media_file_id: row.media_file_id,
+            file_path: row.file_path,
+            reason,
+        }
+    }
+}
+
+impl std::fmt::Display for MissingReason {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::MissingMediaRow => f.write_str("missing media_file row"),
+            Self::InvalidMediaType(file_type) => write!(f, "invalid media_file type {file_type:?}"),
+            Self::EmptyPath => f.write_str("empty media file path"),
+            Self::MissingFile => f.write_str("audio file not found on disk"),
+            Self::NotRegularFile => f.write_str("audio path is not a regular file"),
+        }
+    }
+}
+
+fn unique_sorted(values: Vec<i64>) -> Vec<i64> {
+    values
+        .into_iter()
+        .collect::<BTreeSet<_>>()
+        .into_iter()
+        .collect()
+}
+
+async fn delete_tracks_and_unreferenced_audio_media(
+    pool: &PgPool,
+    track_ids: &[i64],
+    media_file_ids: &[i64],
+) -> anyhow::Result<DeleteStats> {
+    if track_ids.is_empty() {
+        return Ok(DeleteStats::default());
+    }
+
+    let mut tx = pool.begin().await?;
+    let mut stats = DeleteStats::default();
+
+    stats.playback_states_cleared = sqlx::query(
+        r#"UPDATE furumusic__playback_state
+              SET current_track_id = NULL
+            WHERE current_track_id = ANY($1)"#,
+    )
+    .bind(track_ids)
+    .execute(&mut *tx)
+    .await?
+    .rows_affected();
+
+    stats.playlist_entries_deleted =
+        delete_track_rows(&mut tx, "furumusic__playlist_track", track_ids).await?;
+    stats.likes_deleted =
+        delete_track_rows(&mut tx, "furumusic__user_liked_track", track_ids).await?;
+    stats.play_history_deleted =
+        delete_track_rows(&mut tx, "furumusic__play_history", track_ids).await?;
+    stats.popularity_history_deleted =
+        delete_track_rows(&mut tx, "furumusic__track_popularity_history", track_ids).await?;
+    stats.scrobble_outbox_deleted =
+        delete_track_rows(&mut tx, "furumusic__lastfm_scrobble_outbox", track_ids).await?;
+    stats.track_genres_deleted =
+        delete_track_rows(&mut tx, "furumusic__track_genre", track_ids).await?;
+
+    stats.entity_tags_deleted = sqlx::query(
+        r#"DELETE FROM furumusic__entity_genre_tag
+            WHERE entity_kind = 'track'
+              AND entity_id = ANY($1)"#,
+    )
+    .bind(track_ids)
+    .execute(&mut *tx)
+    .await?
+    .rows_affected();
+
+    stats.external_ids_deleted = sqlx::query(
+        r#"DELETE FROM furumusic__external_metadata_id
+            WHERE entity_kind = 'track'
+              AND entity_id = ANY($1)"#,
+    )
+    .bind(track_ids)
+    .execute(&mut *tx)
+    .await?
+    .rows_affected();
+
+    stats.track_artists_deleted =
+        delete_track_rows(&mut tx, "furumusic__track_artist", track_ids).await?;
+
+    stats.tracks_deleted = sqlx::query("DELETE FROM furumusic__track WHERE id = ANY($1)")
+        .bind(track_ids)
+        .execute(&mut *tx)
+        .await?
+        .rows_affected();
+
+    if !media_file_ids.is_empty() {
+        stats.media_files_deleted = sqlx::query(
+            r#"DELETE FROM furumusic__media_file mf
+                WHERE mf.id = ANY($1)
+                  AND mf.file_type = 'audio'
+                  AND NOT EXISTS (
+                        SELECT 1
+                          FROM furumusic__track t
+                         WHERE t.audio_file_id = mf.id
+                            OR t.cover_file_id = mf.id
+                  )
+                  AND NOT EXISTS (
+                        SELECT 1
+                          FROM furumusic__release r
+                         WHERE r.cover_file_id = mf.id
+                  )
+                  AND NOT EXISTS (
+                        SELECT 1
+                          FROM furumusic__artist a
+                         WHERE a.image_file_id = mf.id
+                  )
+                  AND NOT EXISTS (
+                        SELECT 1
+                          FROM furumusic__playlist p
+                         WHERE p.cover_file_id = mf.id
+                  )"#,
+        )
+        .bind(media_file_ids)
+        .execute(&mut *tx)
+        .await?
+        .rows_affected();
+    }
+
+    tx.commit().await?;
+    Ok(stats)
+}
+
+async fn delete_track_rows(
+    tx: &mut sqlx::Transaction<'_, sqlx::Postgres>,
+    table: &str,
+    track_ids: &[i64],
+) -> anyhow::Result<u64> {
+    let sql = format!("DELETE FROM {table} WHERE track_id = ANY($1)");
+    Ok(sqlx::query(&sql)
+        .bind(track_ids)
+        .execute(&mut **tx)
+        .await?
+        .rows_affected())
+}
+
+async fn count_empty_releases(pool: &PgPool, release_ids: &[i64]) -> anyhow::Result<i64> {
+    if release_ids.is_empty() {
+        return Ok(0);
+    }
+
+    let count = sqlx::query_scalar::<_, i64>(
+        r#"SELECT COUNT(*)
+             FROM furumusic__release r
+            WHERE r.id = ANY($1)
+              AND NOT EXISTS (
+                    SELECT 1
+                      FROM furumusic__track t
+                     WHERE t.release_id = r.id
+              )"#,
+    )
+    .bind(release_ids)
+    .fetch_one(pool)
+    .await?;
+
+    Ok(count)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn unique_sorted_deduplicates_ids() {
+        assert_eq!(unique_sorted(vec![3, 1, 3, 2, 1]), vec![1, 2, 3]);
+    }
+
+    #[test]
+    fn missing_reason_display_is_stable() {
+        assert_eq!(
+            MissingReason::InvalidMediaType("cover_art".to_owned()).to_string(),
+            "invalid media_file type \"cover_art\""
+        );
+        assert_eq!(
+            MissingReason::MissingFile.to_string(),
+            "audio file not found on disk"
+        );
+    }
+}

src/jobs/artwork_backfill.rs

@@ -15,12 +15,19 @@ pub struct ArtworkBackfillJob;
 const LASTFM_REQUEST_DELAY: std::time::Duration = std::time::Duration::from_millis(1200);
 const MAX_LASTFM_RELEASE_LOOKUPS: i64 = 200;
 const MAX_LASTFM_ARTIST_LOOKUPS: i64 = 200;
+const MAX_CAA_RELEASE_LOOKUPS: i64 = 200;
+
+#[derive(Debug, Clone, Copy)]
+pub struct ArtworkBackfillOptions {
+    pub overwrite_existing: bool,
+}
 
 #[derive(Debug, sqlx::FromRow)]
 struct ReleaseCandidate {
     id: i64,
     title: String,
     artist_name: Option<String>,
+    track_title: Option<String>,
 }
 
 #[derive(Debug, sqlx::FromRow)]
@@ -36,6 +43,13 @@ struct ArtworkRefCandidate {
     file_path: Option<String>,
 }
 
+#[derive(Debug, sqlx::FromRow)]
+struct ArtistImageRepairCandidate {
+    id: i64,
+    name: String,
+    media_file_id: i64,
+}
+
 #[derive(Debug, Deserialize)]
 struct LastfmAlbumResponse {
     album: Option<LastfmImageContainer>,
@@ -85,7 +99,10 @@ struct ArtworkStats {
     broken_release_refs_cleared: u64,
     broken_track_refs_cleared: u64,
     broken_artist_refs_cleared: u64,
+    remote_artist_album_fallback_refs_cleared: u64,
     release_local_assigned: u64,
+    release_caa_assigned: u64,
+    release_caa_not_found: u64,
     release_lastfm_assigned: u64,
     release_lastfm_not_found: u64,
     release_skipped_no_audio: u64,
@@ -114,66 +131,107 @@ impl Job for ArtworkBackfillJob {
     }
 
     async fn run(&self, ctx: &JobContext, log: &mut JobLog) -> anyhow::Result<()> {
-        let storage_dir = ctx.config.agent_storage_dir.trim();
-        if storage_dir.is_empty() {
-            log.warn("agent_storage_dir is not configured, skipping artwork backfill");
-            return Ok(());
-        }
-
-        let client = Client::builder()
-            .user_agent(format!(
-                "furumusic-artwork-backfill/{}",
-                env!("CARGO_PKG_VERSION")
-            ))
-            .timeout(std::time::Duration::from_secs(20))
-            .build()?;
-        let mut stats = ArtworkStats::default();
-
-        let normalized_paths =
-            crate::media_paths::normalize_media_file_paths(&ctx.pool, storage_dir).await?;
-        if normalized_paths > 0 {
-            log.info(&format!(
-                "Media path normalization pass: rewrote {normalized_paths} media file path(s) to relative storage paths"
-            ));
-        } else {
-            log.info("Media path normalization pass: all media file paths are already relative");
-        }
-
-        repair_missing_artwork_refs(ctx, log, storage_dir, &mut stats).await?;
-        backfill_release_local(ctx, log, storage_dir, &mut stats).await?;
-
-        let api_key = ctx.config.lastfm_api_key.trim();
-        if api_key.is_empty() {
-            log.warn("lastfm_api_key is not configured; skipping Last.fm artwork fallback");
-        } else {
-            backfill_release_lastfm(ctx, log, storage_dir, api_key, &client, &mut stats).await?;
-            backfill_artist_lastfm(ctx, log, storage_dir, api_key, &client, &mut stats).await?;
-        }
-
-        backfill_artist_album_fallbacks(ctx, log, &mut stats).await?;
-        repair_cover_variants(ctx, log, storage_dir, &mut stats).await?;
-
-        log.info(&format!(
-            "Artwork backfill complete: broken_release_refs_cleared={}, broken_track_refs_cleared={}, broken_artist_refs_cleared={}, release_local_assigned={}, release_lastfm_assigned={}, release_lastfm_not_found={}, release_skipped_no_audio={}, artist_lastfm_assigned={}, artist_lastfm_not_found={}, artist_album_fallback_assigned={}, variants_created={}, variants_unchanged={}, variants_missing_original={}, failed={}",
-            stats.broken_release_refs_cleared,
-            stats.broken_track_refs_cleared,
-            stats.broken_artist_refs_cleared,
-            stats.release_local_assigned,
-            stats.release_lastfm_assigned,
-            stats.release_lastfm_not_found,
-            stats.release_skipped_no_audio,
-            stats.artist_lastfm_assigned,
-            stats.artist_lastfm_not_found,
-            stats.artist_album_fallback_assigned,
-            stats.variants_created,
-            stats.variants_unchanged,
-            stats.variants_missing_original,
-            stats.failed
-        ));
-        Ok(())
+        run_with_options(
+            ctx,
+            log,
+            ArtworkBackfillOptions {
+                overwrite_existing: false,
+            },
+        )
+        .await
     }
 }
 
+pub async fn run_with_options(
+    ctx: &JobContext,
+    log: &mut JobLog,
+    options: ArtworkBackfillOptions,
+) -> anyhow::Result<()> {
+    let storage_dir = ctx.config.agent_storage_dir.trim();
+    if storage_dir.is_empty() {
+        log.warn("agent_storage_dir is not configured, skipping artwork backfill");
+        return Ok(());
+    }
+
+    log.info(&format!(
+        "Artwork backfill options: mode={}",
+        if options.overwrite_existing {
+            "overwrite_existing"
+        } else {
+            "missing_only"
+        }
+    ));
+
+    let client = Client::builder()
+        .user_agent(format!(
+            "furumusic-artwork-backfill/{}",
+            env!("CARGO_PKG_VERSION")
+        ))
+        .timeout(std::time::Duration::from_secs(20))
+        .build()?;
+    let musicbrainz_client =
+        crate::jobs::musicbrainz::MusicBrainzClient::new("furumusic-artwork-backfill")?;
+    let mut stats = ArtworkStats::default();
+
+    let normalized_paths =
+        crate::media_paths::normalize_media_file_paths(&ctx.pool, storage_dir).await?;
+    if normalized_paths > 0 {
+        log.info(&format!(
+            "Media path normalization pass: rewrote {normalized_paths} media file path(s) to relative storage paths"
+        ));
+    } else {
+        log.info("Media path normalization pass: all media file paths are already relative");
+    }
+
+    repair_missing_artwork_refs(ctx, log, storage_dir, &mut stats).await?;
+    repair_remote_artist_album_fallback_refs(ctx, log, &mut stats).await?;
+    backfill_release_local(ctx, log, storage_dir, options, &mut stats).await?;
+    backfill_release_coverartarchive(
+        ctx,
+        log,
+        storage_dir,
+        &musicbrainz_client,
+        options,
+        &mut stats,
+    )
+    .await?;
+
+    let api_key = ctx.config.lastfm_api_key.trim();
+    if api_key.is_empty() {
+        log.warn("lastfm_api_key is not configured; skipping Last.fm artwork fallback");
+    } else {
+        backfill_release_lastfm(ctx, log, storage_dir, api_key, &client, options, &mut stats)
+            .await?;
+        backfill_artist_lastfm(ctx, log, storage_dir, api_key, &client, options, &mut stats)
+            .await?;
+    }
+
+    backfill_artist_album_fallbacks(ctx, log, options, &mut stats).await?;
+    repair_cover_variants(ctx, log, storage_dir, &mut stats).await?;
+
+    log.info(&format!(
+        "Artwork backfill complete: broken_release_refs_cleared={}, broken_track_refs_cleared={}, broken_artist_refs_cleared={}, remote_artist_album_fallback_refs_cleared={}, release_local_assigned={}, release_caa_assigned={}, release_caa_not_found={}, release_lastfm_assigned={}, release_lastfm_not_found={}, release_skipped_no_audio={}, artist_lastfm_assigned={}, artist_lastfm_not_found={}, artist_album_fallback_assigned={}, variants_created={}, variants_unchanged={}, variants_missing_original={}, failed={}",
+        stats.broken_release_refs_cleared,
+        stats.broken_track_refs_cleared,
+        stats.broken_artist_refs_cleared,
+        stats.remote_artist_album_fallback_refs_cleared,
+        stats.release_local_assigned,
+        stats.release_caa_assigned,
+        stats.release_caa_not_found,
+        stats.release_lastfm_assigned,
+        stats.release_lastfm_not_found,
+        stats.release_skipped_no_audio,
+        stats.artist_lastfm_assigned,
+        stats.artist_lastfm_not_found,
+        stats.artist_album_fallback_assigned,
+        stats.variants_created,
+        stats.variants_unchanged,
+        stats.variants_missing_original,
+        stats.failed
+    ));
+    Ok(())
+}
+
 async fn repair_missing_artwork_refs(
     ctx: &JobContext,
     log: &mut JobLog,
@@ -186,6 +244,71 @@ async fn repair_missing_artwork_refs(
     Ok(())
 }
 
+async fn repair_remote_artist_album_fallback_refs(
+    ctx: &JobContext,
+    log: &mut JobLog,
+    stats: &mut ArtworkStats,
+) -> anyhow::Result<()> {
+    let rows = sqlx::query_as::<_, ArtistImageRepairCandidate>(
+        r#"SELECT DISTINCT a.id,
+                  a.name::text AS name,
+                  a.image_file_id AS media_file_id
+             FROM furumusic__artist a
+             JOIN furumusic__media_file mf ON mf.id = a.image_file_id
+            WHERE a.image_file_id IS NOT NULL
+              AND a.is_hidden = false
+              AND mf.file_path NOT LIKE '%/__artist_image__/%'
+              AND EXISTS (
+                    SELECT 1
+                      FROM furumusic__release r
+                      JOIN furumusic__artwork_lookup_state s
+                        ON s.entity_kind = 'release'
+                       AND s.entity_id = r.id
+                       AND s.source IN ('lastfm', 'coverartarchive')
+                       AND s.status = 'found'
+                     WHERE r.cover_file_id = a.image_file_id
+                       AND r.is_hidden = false
+                  )
+            ORDER BY a.id"#,
+    )
+    .fetch_all(&ctx.pool)
+    .await?;
+
+    if rows.is_empty() {
+        return Ok(());
+    }
+
+    log.info(&format!(
+        "Artist fallback repair pass: clearing {} remote release cover fallback(s)",
+        rows.len()
+    ));
+
+    for row in rows {
+        let result = sqlx::query(
+            r#"UPDATE furumusic__artist
+                  SET image_file_id = NULL,
+                      updated_at = $3
+                WHERE id = $1
+                  AND image_file_id = $2"#,
+        )
+        .bind(row.id)
+        .bind(row.media_file_id)
+        .bind(now_iso())
+        .execute(&ctx.pool)
+        .await?;
+
+        if result.rows_affected() > 0 {
+            stats.remote_artist_album_fallback_refs_cleared += 1;
+            log.warn(&format!(
+                "Artist {} \"{}\": cleared remote release cover fallback (media_file_id={})",
+                row.id, row.name, row.media_file_id
+            ));
+        }
+    }
+
+    Ok(())
+}
+
 async fn repair_missing_release_cover_refs(
     ctx: &JobContext,
     log: &mut JobLog,
@@ -360,6 +483,7 @@ async fn backfill_release_local(
     ctx: &JobContext,
     log: &mut JobLog,
     storage_dir: &str,
+    options: ArtworkBackfillOptions,
     stats: &mut ArtworkStats,
 ) -> anyhow::Result<()> {
     let releases = sqlx::query_as::<_, ReleaseCandidate>(
@@ -372,17 +496,26 @@ async fn backfill_release_local(
                      WHERE ra.release_id = r.id
                      ORDER BY ra.position
                      LIMIT 1
-                  ) AS artist_name
+                  ) AS artist_name,
+                  (
+                    SELECT t.title::text
+                      FROM furumusic__track t
+                     WHERE t.release_id = r.id
+                       AND t.is_hidden = false
+                     ORDER BY t.disc_number NULLS LAST, t.track_number NULLS LAST, t.id
+                     LIMIT 1
+                  ) AS track_title
              FROM furumusic__release r
-            WHERE r.cover_file_id IS NULL
+            WHERE ($1 OR r.cover_file_id IS NULL)
               AND r.is_hidden = false
             ORDER BY r.id"#,
     )
+    .bind(options.overwrite_existing)
     .fetch_all(&ctx.pool)
     .await?;
 
     if releases.is_empty() {
-        log.info("Release local artwork pass: all visible releases already have covers");
+        log.info("Release local artwork pass: no eligible releases need local cover lookup");
         return Ok(());
     }
     log.info(&format!(
@@ -451,7 +584,7 @@ async fn backfill_release_local(
         .await
         {
             Ok(cover_file_id) => {
-                cover_art::assign_cover_to_release(&ctx.pool, release.id, cover_file_id).await?;
+                assign_cover_to_release(&ctx.pool, release.id, cover_file_id, options).await?;
                 stats.release_local_assigned += 1;
                 log.info(&format!(
                     "Release {} \"{}\": assigned local cover from {source_desc}",
@@ -471,12 +604,12 @@ async fn backfill_release_local(
     Ok(())
 }
 
-async fn backfill_release_lastfm(
+async fn backfill_release_coverartarchive(
     ctx: &JobContext,
     log: &mut JobLog,
     storage_dir: &str,
-    api_key: &str,
-    client: &Client,
+    client: &crate::jobs::musicbrainz::MusicBrainzClient,
+    options: ArtworkBackfillOptions,
     stats: &mut ArtworkStats,
 ) -> anyhow::Result<()> {
     let failed_cutoff = cutoff_iso(1);
@@ -502,25 +635,285 @@ async fn backfill_release_lastfm(
                        ORDER BY t.disc_number NULLS LAST, t.track_number NULLS LAST, ta.position
                        LIMIT 1
                     )
-                  ) AS artist_name
+                  ) AS artist_name,
+                  (
+                    SELECT t.title::text
+                      FROM furumusic__track t
+                     WHERE t.release_id = r.id
+                       AND t.is_hidden = false
+                     ORDER BY t.disc_number NULLS LAST, t.track_number NULLS LAST, t.id
+                     LIMIT 1
+                  ) AS track_title
              FROM furumusic__release r
              LEFT JOIN furumusic__artwork_lookup_state s
                ON s.entity_kind = 'release'
               AND s.entity_id = r.id
-              AND s.source = 'lastfm'
-            WHERE r.cover_file_id IS NULL
+              AND s.source = 'coverartarchive'
+            WHERE ($3 OR r.cover_file_id IS NULL)
               AND r.is_hidden = false
               AND (
-                    s.entity_id IS NULL
+                    $3
+                 OR s.entity_id IS NULL
                  OR s.status = 'failed' AND s.last_attempt_at < $1
                  OR s.status = 'not_found' AND (s.attempt_count < 3 OR s.last_attempt_at < $2)
                  OR s.status = 'found' AND s.last_attempt_at < $1
               )
             ORDER BY s.last_attempt_at NULLS FIRST, r.id
-            LIMIT $3"#,
+            LIMIT $4"#,
     )
     .bind(&failed_cutoff)
     .bind(&not_found_cutoff)
+    .bind(options.overwrite_existing)
+    .bind(MAX_CAA_RELEASE_LOOKUPS)
+    .fetch_all(&ctx.pool)
+    .await?;
+
+    if releases.is_empty() {
+        log.info("Release Cover Art Archive pass: no eligible releases need lookup");
+        return Ok(());
+    }
+    log.info(&format!(
+        "Release Cover Art Archive pass: looking up {} release(s)",
+        releases.len()
+    ));
+
+    for (index, release) in releases.iter().enumerate() {
+        let Some(artist_name) = release
+            .artist_name
+            .as_deref()
+            .map(str::trim)
+            .filter(|value| !value.is_empty())
+        else {
+            stats.release_caa_not_found += 1;
+            record_coverartarchive_lookup_state(
+                &ctx.pool,
+                "release",
+                release.id,
+                "not_found",
+                Some("release has no primary artist for MusicBrainz lookup"),
+                None,
+            )
+            .await?;
+            continue;
+        };
+
+        log.info(&format!(
+            "Release Cover Art Archive {}/{}: release {} \"{}\" by \"{}\"",
+            index + 1,
+            releases.len(),
+            release.id,
+            release.title,
+            artist_name
+        ));
+
+        let release_mbid = crate::jobs::musicbrainz::load_or_search_release_mbid(
+            &ctx.pool,
+            client,
+            release.id,
+            artist_name,
+            &release.title,
+            release.track_title.as_deref(),
+        )
+        .await;
+        let (release_mbid, release_group_mbid) = match release_mbid {
+            Ok(value) => value,
+            Err(err) => {
+                stats.failed += 1;
+                record_coverartarchive_lookup_state(
+                    &ctx.pool,
+                    "release",
+                    release.id,
+                    "failed",
+                    Some(&err.to_string()),
+                    None,
+                )
+                .await?;
+                log.warn(&format!(
+                    "Release {} \"{}\": MusicBrainz lookup for cover art failed: {err}",
+                    release.id, release.title
+                ));
+                continue;
+            }
+        };
+
+        if release_mbid.is_none() && release_group_mbid.is_none() {
+            stats.release_caa_not_found += 1;
+            record_coverartarchive_lookup_state(
+                &ctx.pool,
+                "release",
+                release.id,
+                "not_found",
+                Some("MusicBrainz release match not found"),
+                None,
+            )
+            .await?;
+            continue;
+        }
+
+        match client
+            .fetch_cover_art_front_url(release_mbid.as_deref(), release_group_mbid.as_deref())
+            .await
+        {
+            Ok(Some(image_url)) => {
+                match download_remote_cover(client.http_client(), &image_url).await {
+                    Ok(cover) => match cover_art::save_cover_to_storage(
+                        &ctx.db,
+                        &ctx.pool,
+                        storage_dir,
+                        artist_name,
+                        &release.title,
+                        &cover,
+                    )
+                    .await
+                    {
+                        Ok(cover_file_id) => {
+                            assign_cover_to_release(&ctx.pool, release.id, cover_file_id, options)
+                                .await?;
+                            record_coverartarchive_lookup_state(
+                                &ctx.pool,
+                                "release",
+                                release.id,
+                                "found",
+                                None,
+                                Some(&image_url),
+                            )
+                            .await?;
+                            stats.release_caa_assigned += 1;
+                            log.info(&format!(
+                                "Release {} \"{}\": assigned Cover Art Archive cover",
+                                release.id, release.title
+                            ));
+                        }
+                        Err(err) => {
+                            stats.failed += 1;
+                            record_coverartarchive_lookup_state(
+                                &ctx.pool,
+                                "release",
+                                release.id,
+                                "failed",
+                                Some(&err.to_string()),
+                                Some(&image_url),
+                            )
+                            .await?;
+                            log.warn(&format!(
+                                "Release {} \"{}\": failed to save Cover Art Archive cover: {err}",
+                                release.id, release.title
+                            ));
+                        }
+                    },
+                    Err(err) => {
+                        stats.failed += 1;
+                        record_coverartarchive_lookup_state(
+                            &ctx.pool,
+                            "release",
+                            release.id,
+                            "failed",
+                            Some(&err.to_string()),
+                            Some(&image_url),
+                        )
+                        .await?;
+                        log.warn(&format!(
+                            "Release {} \"{}\": failed to download Cover Art Archive cover: {err}",
+                            release.id, release.title
+                        ));
+                    }
+                }
+            }
+            Ok(None) => {
+                stats.release_caa_not_found += 1;
+                record_coverartarchive_lookup_state(
+                    &ctx.pool,
+                    "release",
+                    release.id,
+                    "not_found",
+                    None,
+                    None,
+                )
+                .await?;
+            }
+            Err(err) => {
+                stats.failed += 1;
+                record_coverartarchive_lookup_state(
+                    &ctx.pool,
+                    "release",
+                    release.id,
+                    "failed",
+                    Some(&err.to_string()),
+                    None,
+                )
+                .await?;
+                log.warn(&format!(
+                    "Release {} \"{}\": Cover Art Archive lookup failed: {err}",
+                    release.id, release.title
+                ));
+            }
+        }
+    }
+
+    Ok(())
+}
+
+async fn backfill_release_lastfm(
+    ctx: &JobContext,
+    log: &mut JobLog,
+    storage_dir: &str,
+    api_key: &str,
+    client: &Client,
+    options: ArtworkBackfillOptions,
+    stats: &mut ArtworkStats,
+) -> anyhow::Result<()> {
+    let failed_cutoff = cutoff_iso(1);
+    let not_found_cutoff = cutoff_iso(30);
+    let releases = sqlx::query_as::<_, ReleaseCandidate>(
+        r#"SELECT r.id,
+                  r.title::text AS title,
+                  COALESCE(
+                    (
+                      SELECT a.name::text
+                        FROM furumusic__release_artist ra
+                        JOIN furumusic__artist a ON a.id = ra.artist_id
+                       WHERE ra.release_id = r.id
+                       ORDER BY ra.position
+                       LIMIT 1
+                    ),
+                    (
+                      SELECT a.name::text
+                        FROM furumusic__track t
+                        JOIN furumusic__track_artist ta ON ta.track_id = t.id
+                        JOIN furumusic__artist a ON a.id = ta.artist_id
+                       WHERE t.release_id = r.id AND ta.role <> 'featuring'
+                       ORDER BY t.disc_number NULLS LAST, t.track_number NULLS LAST, ta.position
+                       LIMIT 1
+                    )
+                  ) AS artist_name,
+                  (
+                    SELECT t.title::text
+                      FROM furumusic__track t
+                     WHERE t.release_id = r.id
+                       AND t.is_hidden = false
+                     ORDER BY t.disc_number NULLS LAST, t.track_number NULLS LAST, t.id
+                     LIMIT 1
+                  ) AS track_title
+             FROM furumusic__release r
+             LEFT JOIN furumusic__artwork_lookup_state s
+               ON s.entity_kind = 'release'
+              AND s.entity_id = r.id
+              AND s.source = 'lastfm'
+            WHERE ($3 OR r.cover_file_id IS NULL)
+              AND r.is_hidden = false
+              AND (
+                    $3
+                 OR s.entity_id IS NULL
+                 OR s.status = 'failed' AND s.last_attempt_at < $1
+                 OR s.status = 'not_found' AND (s.attempt_count < 3 OR s.last_attempt_at < $2)
+                 OR s.status = 'found' AND s.last_attempt_at < $1
+              )
+            ORDER BY s.last_attempt_at NULLS FIRST, r.id
+            LIMIT $4"#,
+    )
+    .bind(&failed_cutoff)
+    .bind(&not_found_cutoff)
+    .bind(options.overwrite_existing)
     .bind(MAX_LASTFM_RELEASE_LOOKUPS)
     .fetch_all(&ctx.pool)
     .await?;
@@ -580,7 +973,7 @@ async fn backfill_release_lastfm(
                 .await
                 {
                     Ok(cover_file_id) => {
-                        cover_art::assign_cover_to_release(&ctx.pool, release.id, cover_file_id)
+                        assign_cover_to_release(&ctx.pool, release.id, cover_file_id, options)
                             .await?;
                         record_lookup_state(
                             &ctx.pool,
@@ -680,12 +1073,37 @@ async fn backfill_release_lastfm(
     Ok(())
 }
 
+async fn assign_cover_to_release(
+    pool: &sqlx::PgPool,
+    release_id: i64,
+    cover_file_id: i64,
+    options: ArtworkBackfillOptions,
+) -> anyhow::Result<()> {
+    if options.overwrite_existing {
+        sqlx::query(
+            r#"UPDATE furumusic__release
+                  SET cover_file_id = $1,
+                      updated_at = $3
+                WHERE id = $2"#,
+        )
+        .bind(cover_file_id)
+        .bind(release_id)
+        .bind(now_iso())
+        .execute(pool)
+        .await?;
+    } else {
+        cover_art::assign_cover_to_release(pool, release_id, cover_file_id).await?;
+    }
+    Ok(())
+}
+
 async fn backfill_artist_lastfm(
     ctx: &JobContext,
     log: &mut JobLog,
     storage_dir: &str,
     api_key: &str,
     client: &Client,
+    options: ArtworkBackfillOptions,
     stats: &mut ArtworkStats,
 ) -> anyhow::Result<()> {
     let failed_cutoff = cutoff_iso(1);
@@ -699,21 +1117,25 @@ async fn backfill_artist_lastfm(
               AND s.entity_id = a.id
               AND s.source = 'lastfm'
             WHERE (
+                    $3
+                 OR
                     a.image_file_id IS NULL
                  OR mf.file_path NOT LIKE '%/__artist_image__/%'
                   )
               AND a.is_hidden = false
               AND (
-                    s.entity_id IS NULL
+                    $3
+                 OR s.entity_id IS NULL
                  OR s.status = 'failed' AND s.last_attempt_at < $1
                  OR s.status = 'not_found' AND (s.attempt_count < 3 OR s.last_attempt_at < $2)
                  OR s.status = 'found' AND s.last_attempt_at < $1
               )
             ORDER BY s.last_attempt_at NULLS FIRST, a.id
-            LIMIT $3"#,
+            LIMIT $4"#,
     )
     .bind(&failed_cutoff)
     .bind(&not_found_cutoff)
+    .bind(options.overwrite_existing)
     .bind(MAX_LASTFM_ARTIST_LOOKUPS)
     .fetch_all(&ctx.pool)
     .await?;
@@ -755,6 +1177,8 @@ async fn backfill_artist_lastfm(
                                           updated_at = $3
                                     WHERE id = $2
                                       AND (
+                                            $4
+                                         OR
                                             image_file_id IS NULL
                                          OR EXISTS (
                                                 SELECT 1
@@ -767,6 +1191,7 @@ async fn backfill_artist_lastfm(
                         .bind(image_file_id)
                         .bind(artist.id)
                         .bind(now_iso())
+                        .bind(options.overwrite_existing)
                         .execute(&ctx.pool)
                         .await?;
                         record_lookup_state(
@@ -826,7 +1251,7 @@ async fn backfill_artist_lastfm(
                     artist.id, artist.name
                 ));
                 stats.artist_lastfm_not_found += 1;
-                match assign_artist_album_fallback(ctx, artist.id).await {
+                match assign_artist_album_fallback(ctx, artist.id, options).await {
                     Ok(Some(media_file_id)) => {
                         stats.artist_album_fallback_assigned += 1;
                         log.info(&format!(
@@ -892,31 +1317,53 @@ async fn backfill_artist_lastfm(
 async fn backfill_artist_album_fallbacks(
     ctx: &JobContext,
     log: &mut JobLog,
+    options: ArtworkBackfillOptions,
     stats: &mut ArtworkStats,
 ) -> anyhow::Result<()> {
     let artists = sqlx::query_as::<_, ArtistCandidate>(
         r#"SELECT a.id, a.name::text AS name
              FROM furumusic__artist a
-            WHERE a.image_file_id IS NULL
+            WHERE ($1 OR a.image_file_id IS NULL)
               AND a.is_hidden = false
               AND EXISTS (
                     SELECT 1
                       FROM furumusic__release_artist ra
                       JOIN furumusic__release r ON r.id = ra.release_id
+                      JOIN furumusic__media_file mf ON mf.id = r.cover_file_id
                      WHERE ra.artist_id = a.id
                        AND r.cover_file_id IS NOT NULL
+                       AND mf.file_type = 'cover_art'
                        AND r.is_hidden = false
+                       AND NOT EXISTS (
+                            SELECT 1
+                              FROM furumusic__artwork_lookup_state s
+                             WHERE s.entity_kind = 'release'
+                               AND s.entity_id = r.id
+                               AND s.source IN ('lastfm', 'coverartarchive')
+                               AND s.status = 'found'
+                       )
                     UNION
                     SELECT 1
                       FROM furumusic__track_artist ta
                       JOIN furumusic__track t ON t.id = ta.track_id
                       JOIN furumusic__release r ON r.id = t.release_id
+                      JOIN furumusic__media_file mf ON mf.id = r.cover_file_id
                      WHERE ta.artist_id = a.id
                        AND r.cover_file_id IS NOT NULL
+                       AND mf.file_type = 'cover_art'
                        AND r.is_hidden = false
+                       AND NOT EXISTS (
+                            SELECT 1
+                              FROM furumusic__artwork_lookup_state s
+                             WHERE s.entity_kind = 'release'
+                               AND s.entity_id = r.id
+                               AND s.source IN ('lastfm', 'coverartarchive')
+                               AND s.status = 'found'
+                       )
                   )
             ORDER BY a.id"#,
     )
+    .bind(options.overwrite_existing)
     .fetch_all(&ctx.pool)
     .await?;
 
@@ -931,7 +1378,7 @@ async fn backfill_artist_album_fallbacks(
     ));
 
     for artist in artists {
-        match assign_artist_album_fallback(ctx, artist.id).await {
+        match assign_artist_album_fallback(ctx, artist.id, options).await {
             Ok(Some(media_file_id)) => {
                 stats.artist_album_fallback_assigned += 1;
                 log.info(&format!(
@@ -1016,6 +1463,7 @@ async fn repair_cover_variants(
 async fn assign_artist_album_fallback(
     ctx: &JobContext,
     artist_id: i64,
+    options: ArtworkBackfillOptions,
 ) -> anyhow::Result<Option<i64>> {
     let media_file_id: Option<i64> = sqlx::query_scalar(
         r#"SELECT media_file_id
@@ -1023,17 +1471,37 @@ async fn assign_artist_album_fallback(
                     SELECT DISTINCT r.cover_file_id AS media_file_id
                       FROM furumusic__release r
                       JOIN furumusic__release_artist ra ON ra.release_id = r.id
+                      JOIN furumusic__media_file mf ON mf.id = r.cover_file_id
                      WHERE ra.artist_id = $1
                        AND r.cover_file_id IS NOT NULL
+                       AND mf.file_type = 'cover_art'
                        AND r.is_hidden = false
+                       AND NOT EXISTS (
+                            SELECT 1
+                              FROM furumusic__artwork_lookup_state s
+                             WHERE s.entity_kind = 'release'
+                               AND s.entity_id = r.id
+                               AND s.source IN ('lastfm', 'coverartarchive')
+                               AND s.status = 'found'
+                       )
                     UNION
                     SELECT DISTINCT r.cover_file_id AS media_file_id
                       FROM furumusic__release r
                       JOIN furumusic__track t ON t.release_id = r.id
                       JOIN furumusic__track_artist ta ON ta.track_id = t.id
+                      JOIN furumusic__media_file mf ON mf.id = r.cover_file_id
                      WHERE ta.artist_id = $1
                        AND r.cover_file_id IS NOT NULL
+                       AND mf.file_type = 'cover_art'
                        AND r.is_hidden = false
+                       AND NOT EXISTS (
+                            SELECT 1
+                              FROM furumusic__artwork_lookup_state s
+                             WHERE s.entity_kind = 'release'
+                               AND s.entity_id = r.id
+                               AND s.source IN ('lastfm', 'coverartarchive')
+                               AND s.status = 'found'
+                       )
                   ) covers
             ORDER BY random()
             LIMIT 1"#,
@@ -1051,11 +1519,12 @@ async fn assign_artist_album_fallback(
               SET image_file_id = $1,
                   updated_at = $3
             WHERE id = $2
-              AND image_file_id IS NULL"#,
+              AND ($4 OR image_file_id IS NULL)"#,
     )
     .bind(media_file_id)
     .bind(artist_id)
     .bind(now_iso())
+    .bind(options.overwrite_existing)
     .execute(&ctx.pool)
     .await?;
 
@@ -1324,6 +1793,36 @@ async fn record_lookup_state(
     Ok(())
 }
 
+async fn record_coverartarchive_lookup_state(
+    pool: &sqlx::PgPool,
+    entity_kind: &str,
+    entity_id: i64,
+    status: &str,
+    error: Option<&str>,
+    source_url: Option<&str>,
+) -> anyhow::Result<()> {
+    sqlx::query(
+        r#"INSERT INTO furumusic__artwork_lookup_state
+              (entity_kind, entity_id, source, status, attempt_count, last_attempt_at, last_error, source_url)
+           VALUES ($1, $2, 'coverartarchive', $3, 1, $4, $5, $6)
+           ON CONFLICT (entity_kind, entity_id, source) DO UPDATE SET
+              status = EXCLUDED.status,
+              attempt_count = furumusic__artwork_lookup_state.attempt_count + 1,
+              last_attempt_at = EXCLUDED.last_attempt_at,
+              last_error = EXCLUDED.last_error,
+              source_url = EXCLUDED.source_url"#,
+    )
+    .bind(entity_kind)
+    .bind(entity_id)
+    .bind(status)
+    .bind(now_iso())
+    .bind(error)
+    .bind(source_url)
+    .execute(pool)
+    .await?;
+    Ok(())
+}
+
 async fn reset_lookup_state(
     pool: &sqlx::PgPool,
     entity_kind: &str,
@@ -1333,7 +1832,7 @@ async fn reset_lookup_state(
         r#"DELETE FROM furumusic__artwork_lookup_state
             WHERE entity_kind = $1
               AND entity_id = $2
-              AND source = 'lastfm'"#,
+              AND source IN ('lastfm', 'coverartarchive')"#,
     )
     .bind(entity_kind)
     .bind(entity_id)

src/jobs/inbox_discover.rs

@@ -12,6 +12,21 @@ const AUDIO_EXTENSIONS: &[&str] = &[
     "mp3", "flac", "ogg", "opus", "aac", "m4a", "wav", "ape", "wv", "wma", "tta", "aiff", "aif",
 ];
 
+/// How long a `failed` review must stay untouched before discover
+/// automatically requeues it (instead of creating a new row per attempt).
+const FAILED_RETRY_COOLDOWN_SECS: i64 = 3600;
+
+/// Leftover files that are safe to purge from inbox folders that no longer
+/// contain any audio (covers, playlists, rip logs and similar sidecar files).
+const JUNK_EXTENSIONS: &[&str] = &[
+    "jpg", "jpeg", "png", "gif", "webp", "bmp", "m3u", "m3u8", "cue", "log", "txt", "nfo", "sfv",
+    "md5", "accurip", "url", "ini", "pdf",
+];
+const JUNK_FILENAMES: &[&str] = &[".ds_store", "thumbs.db", "desktop.ini"];
+
+/// Junk younger than this is kept — an upload might still be in progress.
+const JUNK_MIN_AGE: std::time::Duration = std::time::Duration::from_secs(24 * 3600);
+
 pub struct InboxDiscoverJob;
 
 #[async_trait::async_trait]
@@ -29,6 +44,8 @@ impl Job for InboxDiscoverJob {
     }
 
     async fn run(&self, ctx: &JobContext, log: &mut JobLog) -> anyhow::Result<()> {
+        let run_start = std::time::Instant::now();
+        let run_outcome = "completed";
         // Prevent overlapping discover runs
         if DISCOVER_RUNNING
             .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst)
@@ -44,6 +61,19 @@ impl Job for InboxDiscoverJob {
             }
         }
         let _guard = Guard;
+        struct MetricsGuard {
+            start: std::time::Instant,
+            outcome: &'static str,
+        }
+        impl Drop for MetricsGuard {
+            fn drop(&mut self) {
+                crate::metrics::record_agent_discover_run(self.outcome, self.start.elapsed());
+            }
+        }
+        let mut metrics_guard = MetricsGuard {
+            start: run_start,
+            outcome: run_outcome,
+        };
 
         let config = &ctx.config;
 
@@ -61,6 +91,10 @@ impl Job for InboxDiscoverJob {
         let mut audio_files = Vec::new();
         collect_audio_files(inbox, &mut audio_files).await?;
 
+        // Purge leftover junk (covers, playlists, logs) from subtrees that no
+        // longer contain audio, so processed uploads don't linger forever.
+        cleanup_inbox_junk(inbox, JUNK_MIN_AGE).await;
+
         log.info(&format!("Found {} audio files in inbox", audio_files.len()));
         if audio_files.is_empty() {
             return Ok(());
@@ -72,6 +106,7 @@ impl Job for InboxDiscoverJob {
         let mut discovered = 0u64;
         let mut skipped_hash = 0u64;
         let mut skipped_existing = 0u64;
+        let mut requeued = 0u64;
 
         for (_folder, files) in &groups {
             for file_path in files {
@@ -79,13 +114,34 @@ impl Job for InboxDiscoverJob {
                     crate::media_paths::path_for_root(&config.agent_inbox_dir, file_path)
                         .unwrap_or_else(|| file_path.to_string_lossy().to_string());
 
-                // Skip if a PendingReview already exists for this path
-                match PendingReview::exists_for_path(&ctx.db, &input_path_str).await {
-                    Ok(true) => {
-                        skipped_existing += 1;
+                // One review row per path: any existing row blocks creating a
+                // new one. A stale "failed" row is requeued in place instead,
+                // so retries don't multiply rows. "rejected" stays rejected.
+                match PendingReview::latest_for_path(&ctx.pool, &input_path_str).await {
+                    Ok(None) => {}
+                    Ok(Some((id, status, updated_at))) => {
+                        if status == "failed" {
+                            let stale = chrono::DateTime::parse_from_rfc3339(&updated_at)
+                                .map(|t| {
+                                    chrono::Utc::now().signed_duration_since(t).num_seconds()
+                                        >= FAILED_RETRY_COOLDOWN_SECS
+                                })
+                                .unwrap_or(true);
+                            if stale {
+                                match PendingReview::requeue_by_ids(&ctx.db, &[id]).await {
+                                    Ok(()) => requeued += 1,
+                                    Err(e) => log.warn(&format!(
+                                        "Failed to requeue review {id} for {input_path_str}: {e}"
+                                    )),
+                                }
+                            } else {
+                                skipped_existing += 1;
+                            }
+                        } else {
+                            skipped_existing += 1;
+                        }
                         continue;
                     }
-                    Ok(false) => {}
                     Err(e) => {
                         log.warn(&format!(
                             "Error checking existing review for {}: {e}",
@@ -97,6 +153,7 @@ impl Job for InboxDiscoverJob {
 
                 // Compute SHA-256 hash
                 let path_clone = file_path.to_path_buf();
+                let hash_start = std::time::Instant::now();
                 let (hash, file_size) =
                     match tokio::task::spawn_blocking(move || -> anyhow::Result<(String, i64)> {
                         let data = std::fs::read(&path_clone)?;
@@ -107,8 +164,16 @@ impl Job for InboxDiscoverJob {
                     })
                     .await?
                     {
-                        Ok(v) => v,
+                        Ok(v) => {
+                            crate::metrics::record_agent_file_hash(hash_start.elapsed(), v.1, "ok");
+                            v
+                        }
                         Err(e) => {
+                            crate::metrics::record_agent_file_hash(
+                                hash_start.elapsed(),
+                                0,
+                                "error",
+                            );
                             log.warn(&format!("Failed to hash {}: {e}", file_path.display()));
                             continue;
                         }
@@ -125,13 +190,18 @@ impl Job for InboxDiscoverJob {
 
                 // Extract raw metadata
                 let path_for_meta = file_path.to_path_buf();
+                let metadata_start = std::time::Instant::now();
                 let raw_meta = match tokio::task::spawn_blocking(move || {
                     crate::agent::metadata::extract(&path_for_meta)
                 })
                 .await?
                 {
-                    Ok(m) => m,
+                    Ok(m) => {
+                        crate::metrics::record_agent_metadata(metadata_start.elapsed(), "ok");
+                        m
+                    }
                     Err(e) => {
+                        crate::metrics::record_agent_metadata(metadata_start.elapsed(), "error");
                         log.warn(&format!(
                             "Failed to extract metadata from {}: {e}",
                             file_path.display()
@@ -186,13 +256,19 @@ impl Job for InboxDiscoverJob {
         }
 
         log.info(&format!(
-            "Discovered {} new files, skipped {} (hash known), skipped {} (already queued)",
-            discovered, skipped_hash, skipped_existing
+            "Discovered {} new files, requeued {} failed, skipped {} (hash known), skipped {} (already tracked)",
+            discovered, requeued, skipped_hash, skipped_existing
         ));
+        crate::metrics::record_agent_discover_files(
+            audio_files.len() as u64,
+            discovered,
+            skipped_hash,
+            skipped_existing,
+        );
 
         // Trigger inbox_process in background if new files were discovered
         // and no orchestrator is already running
-        if discovered > 0 {
+        if discovered + requeued > 0 {
             if crate::jobs::inbox_process::is_orchestrator_running() {
                 log.info(
                     "New files discovered but inbox_process already running, it will pick them up",
@@ -219,6 +295,7 @@ impl Job for InboxDiscoverJob {
             }
         }
 
+        metrics_guard.outcome = run_outcome;
         Ok(())
     }
 }
@@ -263,3 +340,75 @@ pub fn is_audio_file(name: &str) -> bool {
     let ext = name.rsplit('.').next().unwrap_or("").to_lowercase();
     AUDIO_EXTENSIONS.contains(&ext.as_str())
 }
+
+fn is_junk_file(name: &str) -> bool {
+    let lower = name.to_lowercase();
+    // macOS AppleDouble sidecars ("._track.mp3") and well-known junk names
+    if lower.starts_with("._") || JUNK_FILENAMES.contains(&lower.as_str()) {
+        return true;
+    }
+    let ext = lower.rsplit('.').next().unwrap_or("");
+    JUNK_EXTENSIONS.contains(&ext)
+}
+
+/// Remove leftover sidecar files (covers, playlists, rip logs) from inbox
+/// subtrees that no longer contain any audio, then prune emptied directories.
+///
+/// Junk younger than `min_age` is kept in case an upload is still in
+/// progress, and unknown file types are never touched. Returns `true` when
+/// `dir` still contains something worth keeping (so the caller must not
+/// remove it).
+async fn cleanup_inbox_junk(dir: &Path, min_age: std::time::Duration) -> bool {
+    let mut entries = match tokio::fs::read_dir(dir).await {
+        Ok(e) => e,
+        Err(_) => return true,
+    };
+
+    let mut has_audio = false;
+    let mut keep_other = false;
+    let mut junk: Vec<PathBuf> = Vec::new();
+
+    while let Ok(Some(entry)) = entries.next_entry().await {
+        let name = entry.file_name().to_string_lossy().into_owned();
+        let ft = match entry.file_type().await {
+            Ok(ft) => ft,
+            Err(_) => {
+                keep_other = true;
+                continue;
+            }
+        };
+        if ft.is_dir() {
+            if Box::pin(cleanup_inbox_junk(&entry.path(), min_age)).await {
+                keep_other = true;
+            } else {
+                let _ = tokio::fs::remove_dir(&entry.path()).await;
+            }
+        } else if !name.starts_with('.') && is_audio_file(&name) {
+            // dotfiles are invisible to discovery, so they don't count as audio
+            has_audio = true;
+        } else if is_junk_file(&name) {
+            junk.push(entry.path());
+        } else {
+            keep_other = true;
+        }
+    }
+
+    if has_audio {
+        return true;
+    }
+
+    let mut junk_left = false;
+    for path in junk {
+        let old_enough = tokio::fs::metadata(&path)
+            .await
+            .ok()
+            .and_then(|m| m.modified().ok())
+            .and_then(|t| t.elapsed().ok())
+            .is_some_and(|age| age >= min_age);
+        if !old_enough || tokio::fs::remove_file(&path).await.is_err() {
+            junk_left = true;
+        }
+    }
+
+    keep_other || junk_left
+}

src/jobs/inbox_process.rs

@@ -12,33 +12,109 @@ static ORCHESTRATOR_RUNNING: AtomicBool = AtomicBool::new(false);
 /// PostgreSQL advisory locks use a 64-bit key; this is an arbitrary unique value.
 const ORCHESTRATOR_ADVISORY_LOCK_ID: i64 = 0x4655_5255_4D55_5349; // "FURUMUSI" in hex
 
+/// Maximum number of files sent to the LLM in a single batch call.
+/// Folders with more files are processed in chunks of this size, otherwise
+/// the model's completion window overflows and the JSON response is cut off.
+const MAX_LLM_BATCH_FILES: usize = 20;
+
 /// Check if an orchestrator is currently running (used by inbox_discover to avoid redundant triggers).
 pub fn is_orchestrator_running() -> bool {
     ORCHESTRATOR_RUNNING.load(Ordering::SeqCst)
 }
 
-/// Try to acquire the PostgreSQL advisory lock for the orchestrator.
-/// Returns true if the lock was acquired (no other orchestrator is running).
-async fn try_acquire_orchestrator_lock(pool: &sqlx::PgPool) -> bool {
-    match sqlx::query_scalar::<_, bool>("SELECT pg_try_advisory_lock($1)")
-        .bind(ORCHESTRATOR_ADVISORY_LOCK_ID)
-        .fetch_one(pool)
-        .await
-    {
-        Ok(acquired) => acquired,
-        Err(e) => {
-            tracing::error!("Failed to acquire advisory lock: {e}");
-            false
-        }
+struct OrchestratorAdvisoryGuard {
+    conn: Option<sqlx::pool::PoolConnection<sqlx::Postgres>>,
+}
+
+impl Drop for OrchestratorAdvisoryGuard {
+    fn drop(&mut self) {
+        let Some(mut conn) = self.conn.take() else {
+            return;
+        };
+
+        tokio::spawn(async move {
+            match sqlx::query_scalar::<_, bool>("SELECT pg_advisory_unlock($1)")
+                .bind(ORCHESTRATOR_ADVISORY_LOCK_ID)
+                .fetch_one(&mut *conn)
+                .await
+            {
+                Ok(true) => tracing::info!("inbox_process: advisory lock released"),
+                Ok(false) => tracing::warn!(
+                    "inbox_process: advisory lock was not held by the guard connection"
+                ),
+                Err(e) => tracing::error!("inbox_process: failed to release advisory lock: {e}"),
+            }
+        });
     }
 }
 
-/// Release the PostgreSQL advisory lock for the orchestrator.
-async fn release_orchestrator_lock(pool: &sqlx::PgPool) {
-    let _ = sqlx::query("SELECT pg_advisory_unlock($1)")
+async fn connection_holds_orchestrator_lock(
+    conn: &mut sqlx::pool::PoolConnection<sqlx::Postgres>,
+) -> anyhow::Result<bool> {
+    let holds_lock = sqlx::query_scalar::<_, bool>(
+        r#"
+        SELECT EXISTS (
+            SELECT 1
+            FROM pg_locks
+            WHERE locktype = 'advisory'
+              AND pid = pg_backend_pid()
+              AND mode = 'ExclusiveLock'
+              AND granted
+              AND objsubid = 1
+              AND classid::bigint = (($1::bigint >> 32) & 4294967295::bigint)
+              AND objid::bigint = ($1::bigint & 4294967295::bigint)
+        )
+        "#,
+    )
+    .bind(ORCHESTRATOR_ADVISORY_LOCK_ID)
+    .fetch_one(&mut **conn)
+    .await?;
+
+    Ok(holds_lock)
+}
+
+/// Try to acquire the PostgreSQL advisory lock for the orchestrator.
+///
+/// The guard owns the same pooled connection that acquired the session-level
+/// lock. This matters because PostgreSQL session advisory locks must be
+/// released on the same connection, not just through the same pool.
+async fn try_acquire_orchestrator_lock(
+    pool: &sqlx::PgPool,
+) -> anyhow::Result<Option<OrchestratorAdvisoryGuard>> {
+    let mut conn = pool.acquire().await?;
+
+    // Older versions acquired the lock through the pool and could return a
+    // locked idle connection. If we get such a connection, drain that stale
+    // re-entrant lock before taking the new guarded lock.
+    let mut cleaned_stale_locks = 0u8;
+    while connection_holds_orchestrator_lock(&mut conn).await? {
+        let unlocked = sqlx::query_scalar::<_, bool>("SELECT pg_advisory_unlock($1)")
+            .bind(ORCHESTRATOR_ADVISORY_LOCK_ID)
+            .fetch_one(&mut *conn)
+            .await?;
+
+        cleaned_stale_locks = cleaned_stale_locks.saturating_add(u8::from(unlocked));
+        if cleaned_stale_locks >= 8 {
+            break;
+        }
+    }
+    if cleaned_stale_locks > 0 {
+        tracing::warn!(
+            count = cleaned_stale_locks,
+            "inbox_process: released stale advisory lock(s) from an idle pooled connection"
+        );
+    }
+
+    let acquired = sqlx::query_scalar::<_, bool>("SELECT pg_try_advisory_lock($1)")
         .bind(ORCHESTRATOR_ADVISORY_LOCK_ID)
-        .execute(pool)
-        .await;
+        .fetch_one(&mut *conn)
+        .await?;
+
+    if acquired {
+        Ok(Some(OrchestratorAdvisoryGuard { conn: Some(conn) }))
+    } else {
+        Ok(None)
+    }
 }
 
 use crate::agent::dto::{FolderContext, NormalizedFields, PathHints, RawMetadata};
@@ -83,10 +159,10 @@ impl Job for InboxProcessJob {
             .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst)
             .is_err()
         {
-            log.info(
+            log.warn(
                 "Another inbox_process orchestrator is already running (AtomicBool), skipping",
             );
-            return Ok(());
+            anyhow::bail!("another inbox_process orchestrator is already running in this process");
         }
         struct AtomicGuard;
         impl Drop for AtomicGuard {
@@ -98,27 +174,16 @@ impl Job for InboxProcessJob {
         let _atomic_guard = AtomicGuard;
 
         // --- Guard 2: PostgreSQL advisory lock (cross-process/binary safe) ---
-        if !try_acquire_orchestrator_lock(&ctx.pool).await {
-            log.info("Another inbox_process orchestrator holds the advisory lock, skipping");
-            return Ok(());
-        }
-        tracing::info!("inbox_process: advisory lock acquired");
-        let pool_for_unlock = ctx.pool.clone();
-        struct AdvisoryGuard {
-            pool: sqlx::PgPool,
-        }
-        impl Drop for AdvisoryGuard {
-            fn drop(&mut self) {
-                let pool = self.pool.clone();
-                tokio::spawn(async move {
-                    release_orchestrator_lock(&pool).await;
-                    tracing::info!("inbox_process: advisory lock released");
-                });
+        let _advisory_guard = match try_acquire_orchestrator_lock(&ctx.pool).await? {
+            Some(guard) => guard,
+            None => {
+                log.warn("Another inbox_process orchestrator holds the advisory lock");
+                anyhow::bail!(
+                    "inbox_process advisory lock is held by another database session; no in-process orchestrator is running"
+                );
             }
-        }
-        let _advisory_guard = AdvisoryGuard {
-            pool: pool_for_unlock,
         };
+        tracing::info!("inbox_process: advisory lock acquired");
 
         let config = Arc::clone(&ctx.config);
         let mut total_ok = 0u64;
@@ -154,14 +219,25 @@ impl Job for InboxProcessJob {
                     folder_rel, file_count,
                 ));
 
-                let (ok, fail) =
-                    process_folder_batch(&ctx.db, &config, &ctx.pool, &folder_rel, reviews, log)
-                        .await;
+                // Large folders are split into chunks: a single LLM call for
+                // 100+ files overflows the completion window and the whole
+                // batch fails with a truncated-JSON parse error.
+                for chunk in reviews.chunks(MAX_LLM_BATCH_FILES) {
+                    let (ok, fail) = process_folder_batch(
+                        &ctx.db,
+                        &config,
+                        &ctx.pool,
+                        &folder_rel,
+                        chunk.to_vec(),
+                        log,
+                    )
+                    .await;
 
-                total_ok += ok;
-                total_fail += fail;
+                    total_ok += ok;
+                    total_fail += fail;
+                }
                 log.info(&format!(
-                    "Folder done: {ok} ok, {fail} err. Total so far: {total_ok} ok, {total_fail} err"
+                    "Folder done. Total so far: {total_ok} ok, {total_fail} err"
                 ));
             }
         }
@@ -284,6 +360,7 @@ async fn process_folder_batch(
     log.info("Phase 1: extracting metadata...");
     let mut prepared: Vec<PreparedFile> = Vec::with_capacity(file_count);
     let mut failed_reviews: Vec<PendingReview> = Vec::new();
+    let mut merged_count = 0u64;
 
     for mut review in reviews {
         let stored_input_path = review.input_path_str().to_owned();
@@ -295,9 +372,6 @@ async fn process_folder_batch(
             .unwrap_or("unknown")
             .to_owned();
 
-        // Set status → processing
-        let _ = review.set_processing(db).await;
-
         // Parse context_json
         let mut context: serde_json::Value = review
             .context_json
@@ -305,14 +379,56 @@ async fn process_folder_batch(
             .and_then(|s| serde_json::from_str(s).ok())
             .unwrap_or_default();
 
+        // Resolve duplicates and missing sources before any expensive work.
+        let sha = context
+            .get("sha256")
+            .and_then(|v| v.as_str())
+            .unwrap_or("")
+            .to_owned();
+        let file_exists = file_path.exists();
+        if !sha.is_empty()
+            && crate::agent::rag::file_hash_exists(pool, &sha)
+                .await
+                .unwrap_or(false)
+        {
+            // Identical content is already in the library — drop the inbox
+            // copy (same as mover::Merged) and close the review.
+            if file_exists {
+                let _ = tokio::fs::remove_file(&file_path).await;
+            }
+            let _ = PendingReview::delete_by_ids(db, &[review.id_val()]).await;
+            log.info(&format!(
+                "{filename}: content already in library (sha256 match) — merged duplicate"
+            ));
+            crate::metrics::record_agent_file_processed("ok", "merged_duplicate");
+            merged_count += 1;
+            continue;
+        }
+        if !file_exists {
+            let msg = format!("{filename}: source file missing: {stored_input_path}");
+            log.error(&msg);
+            let _ = review.set_failed(db, &msg).await;
+            failed_reviews.push(review);
+            continue;
+        }
+
+        // Set status → processing
+        let _ = review.set_processing(db).await;
+
         // Extract metadata (with 60s timeout)
         let path_for_meta = file_path.to_path_buf();
+        let metadata_start = std::time::Instant::now();
         let meta_future =
             tokio::task::spawn_blocking(move || crate::agent::metadata::extract(&path_for_meta));
         let raw_meta =
             match tokio::time::timeout(std::time::Duration::from_secs(60), meta_future).await {
-                Ok(Ok(Ok(m))) => m,
+                Ok(Ok(Ok(m))) => {
+                    crate::metrics::record_agent_metadata(metadata_start.elapsed(), "ok");
+                    m
+                }
                 Ok(Ok(Err(e))) => {
+                    crate::metrics::record_agent_metadata(metadata_start.elapsed(), "error");
+                    crate::metrics::record_agent_failed("metadata");
                     let msg = format!("{filename}: metadata error: {e}");
                     log.error(&msg);
                     let _ = review.set_failed(db, &msg).await;
@@ -320,6 +436,8 @@ async fn process_folder_batch(
                     continue;
                 }
                 Ok(Err(e)) => {
+                    crate::metrics::record_agent_metadata(metadata_start.elapsed(), "panic");
+                    crate::metrics::record_agent_failed("metadata");
                     let msg = format!("{filename}: metadata panic: {e}");
                     log.error(&msg);
                     let _ = review.set_failed(db, &msg).await;
@@ -327,6 +445,8 @@ async fn process_folder_batch(
                     continue;
                 }
                 Err(_) => {
+                    crate::metrics::record_agent_metadata(metadata_start.elapsed(), "timeout");
+                    crate::metrics::record_agent_failed("metadata");
                     let msg = format!("{filename}: metadata timeout (60s)");
                     log.error(&msg);
                     let _ = review.set_failed(db, &msg).await;
@@ -374,15 +494,16 @@ async fn process_folder_batch(
     }
 
     log.info(&format!(
-        "Phase 1 done: {} prepared, {} failed metadata",
+        "Phase 1 done: {} prepared, {} merged duplicates, {} failed",
         prepared.len(),
+        merged_count,
         failed_reviews.len(),
     ));
 
     if prepared.is_empty() {
         let duration_ms = batch_start.elapsed().as_millis() as i64;
         let _ = run.set_completed(db, duration_ms, &log.output()).await;
-        return (0, failed_reviews.len() as u64);
+        return (merged_count, failed_reviews.len() as u64);
     }
 
     // Phase 2: RAG lookup (collect unique artist/album queries from all files)
@@ -416,6 +537,7 @@ async fn process_folder_batch(
     // Lookup all unique artist queries
     let mut all_similar_artists = Vec::new();
     for q in &artist_queries {
+        let rag_start = std::time::Instant::now();
         match tokio::time::timeout(
             std::time::Duration::from_secs(30),
             crate::agent::rag::find_similar_artists(pool, q, 5),
@@ -423,6 +545,12 @@ async fn process_folder_batch(
         .await
         {
             Ok(Ok(results)) => {
+                crate::metrics::record_agent_rag(
+                    "artist",
+                    "ok",
+                    rag_start.elapsed(),
+                    results.len(),
+                );
                 for a in results {
                     if !all_similar_artists
                         .iter()
@@ -432,13 +560,20 @@ async fn process_folder_batch(
                     }
                 }
             }
-            Ok(Err(e)) => log.warn(&format!("RAG artist lookup failed for \"{q}\": {e}")),
-            Err(_) => log.warn(&format!("RAG artist lookup timed out for \"{q}\"")),
+            Ok(Err(e)) => {
+                crate::metrics::record_agent_rag("artist", "error", rag_start.elapsed(), 0);
+                log.warn(&format!("RAG artist lookup failed for \"{q}\": {e}"))
+            }
+            Err(_) => {
+                crate::metrics::record_agent_rag("artist", "timeout", rag_start.elapsed(), 0);
+                log.warn(&format!("RAG artist lookup timed out for \"{q}\""))
+            }
         }
     }
 
     let mut all_similar_releases = Vec::new();
     for q in &album_queries {
+        let rag_start = std::time::Instant::now();
         match tokio::time::timeout(
             std::time::Duration::from_secs(30),
             crate::agent::rag::find_similar_releases(pool, q, 5),
@@ -446,6 +581,12 @@ async fn process_folder_batch(
         .await
         {
             Ok(Ok(results)) => {
+                crate::metrics::record_agent_rag(
+                    "release",
+                    "ok",
+                    rag_start.elapsed(),
+                    results.len(),
+                );
                 for r in results {
                     if !all_similar_releases
                         .iter()
@@ -455,8 +596,14 @@ async fn process_folder_batch(
                     }
                 }
             }
-            Ok(Err(e)) => log.warn(&format!("RAG release lookup failed for \"{q}\": {e}")),
-            Err(_) => log.warn(&format!("RAG release lookup timed out for \"{q}\"")),
+            Ok(Err(e)) => {
+                crate::metrics::record_agent_rag("release", "error", rag_start.elapsed(), 0);
+                log.warn(&format!("RAG release lookup failed for \"{q}\": {e}"))
+            }
+            Err(_) => {
+                crate::metrics::record_agent_rag("release", "timeout", rag_start.elapsed(), 0);
+                log.warn(&format!("RAG release lookup timed out for \"{q}\""))
+            }
         }
     }
 
@@ -547,18 +694,22 @@ async fn process_folder_batch(
     let batch_result = match llm_result {
         Ok(r) => r,
         Err(e) => {
+            crate::metrics::record_agent_failed("llm");
+            crate::metrics::record_agent_folder_batch("failed", file_count, batch_start.elapsed());
             let err_msg = format!("Batch LLM call failed: {e}");
             log.error(&err_msg);
             // Mark all files as failed
+            let prepared_count = prepared.len() as u64;
             for mut p in prepared {
                 let _ = p.review.set_failed(db, &err_msg).await;
+                crate::metrics::record_agent_file_processed("failed", "failed");
             }
-            let total_fail_count = failed_reviews.len() as u64 + file_count as u64;
+            let total_fail_count = failed_reviews.len() as u64 + prepared_count;
             let duration_ms = batch_start.elapsed().as_millis() as i64;
             let _ = run
                 .set_failed(db, duration_ms, &log.output(), &err_msg)
                 .await;
-            return (0, total_fail_count);
+            return (merged_count, total_fail_count);
         }
     };
 
@@ -582,7 +733,7 @@ async fn process_folder_batch(
     let completion_per_file = batch_result.completion_tokens / prepared.len().max(1) as u64;
     let duration_per_file = batch_result.duration_ms as i64 / prepared.len().max(1) as i64;
 
-    let mut ok_count = 0u64;
+    let mut ok_count = merged_count;
     let mut fail_count = failed_reviews.len() as u64;
 
     for mut p in prepared {
@@ -612,6 +763,7 @@ async fn process_folder_batch(
 
         let result_json = serde_json::to_string(normalized).unwrap_or_default();
         let confidence = normalized.confidence.unwrap_or(0.0);
+        crate::metrics::observe_agent_confidence(confidence);
 
         let feat = if normalized.featured_artists.is_empty() {
             String::new()
@@ -655,9 +807,12 @@ async fn process_folder_batch(
             {
                 Ok(()) => {
                     let _ = p.review.set_auto_approved(db).await;
+                    crate::metrics::record_agent_file_processed("ok", "auto_approved");
                     ok_count += 1;
                 }
                 Err(e) => {
+                    crate::metrics::record_agent_failed("finalize");
+                    crate::metrics::record_agent_file_processed("failed", "failed");
                     let msg = format!("{filename}: finalize failed: {e}");
                     log.error(&msg);
                     let _ = p.review.set_failed(db, &msg).await;
@@ -671,6 +826,7 @@ async fn process_folder_batch(
             )
             .unwrap();
             let _ = p.review.save(db).await;
+            crate::metrics::record_agent_file_processed("ok", "pending_review");
             log.info(&format!(
                 "{filename}: manual review (confidence {confidence} < {})",
                 config.agent_confidence_threshold,
@@ -682,9 +838,11 @@ async fn process_folder_batch(
     let duration_ms = batch_start.elapsed().as_millis() as i64;
     if fail_count == 0 {
         let _ = run.set_completed(db, duration_ms, &log.output()).await;
+        crate::metrics::record_agent_folder_batch("completed", file_count, batch_start.elapsed());
     } else {
         let msg = format!("{fail_count} file(s) failed");
         let _ = run.set_failed(db, duration_ms, &log.output(), &msg).await;
+        crate::metrics::record_agent_folder_batch("failed", file_count, batch_start.elapsed());
     }
 
     (ok_count, fail_count)

src/jobs/metadata_backfill.rs

@@ -15,6 +15,7 @@ pub struct MetadataBackfillOptions {
     pub duration_seconds: bool,
     pub local_genres: bool,
     pub lastfm_tags: bool,
+    pub musicbrainz_tags: bool,
     pub overwrite: bool,
 }
 
@@ -26,6 +27,7 @@ impl MetadataBackfillOptions {
             || self.duration_seconds
             || self.local_genres
             || self.lastfm_tags
+            || self.musicbrainz_tags
     }
 
     fn needs_file_scan(self) -> bool {
@@ -59,6 +61,7 @@ struct LastfmReleaseTagRow {
     id: i64,
     title: String,
     artist_name: Option<String>,
+    track_title: Option<String>,
 }
 
 #[derive(sqlx::FromRow)]
@@ -84,6 +87,22 @@ struct LastfmTagStats {
     failed: u64,
 }
 
+#[derive(Debug, Default)]
+struct MusicBrainzTagStats {
+    considered: u64,
+    updated_entities: u64,
+    tags_saved: u64,
+    skipped_existing: u64,
+    not_found: u64,
+    failed: u64,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum LastfmTagPassResult {
+    Completed,
+    RateLimited,
+}
+
 pub struct MetadataBackfillJob;
 
 #[async_trait::async_trait]
@@ -111,6 +130,7 @@ impl Job for MetadataBackfillJob {
                 duration_seconds: true,
                 local_genres: true,
                 lastfm_tags: true,
+                musicbrainz_tags: true,
                 overwrite: false,
             },
         )
@@ -137,10 +157,11 @@ pub async fn run_with_options(
     let mut failed = 0u64;
 
     log.info(&format!(
-        "Metadata backfill options: file_scan={}, local_genres={}, lastfm_tags={}, mode={}",
+        "Metadata backfill options: file_scan={}, local_genres={}, lastfm_tags={}, musicbrainz_tags={}, mode={}",
         options.needs_file_scan(),
         options.local_genres,
         options.lastfm_tags,
+        options.musicbrainz_tags,
         if options.overwrite {
             "overwrite"
         } else {
@@ -245,14 +266,9 @@ pub async fn run_with_options(
             let mut changed_tags = false;
             if options.local_genres {
                 if let (Some(track_id), Some(genre)) = (row.track_id, raw_meta.genre.as_deref()) {
-                    let saved = save_track_tag_text(
-                        &ctx.pool,
-                        track_id,
-                        genre,
-                        "file",
-                        options.overwrite,
-                    )
-                    .await?;
+                    let saved =
+                        save_track_tag_text(&ctx.pool, track_id, genre, "file", options.overwrite)
+                            .await?;
                     if saved > 0 {
                         local_tags_updated += saved;
                         changed_tags = true;
@@ -306,14 +322,28 @@ pub async fn run_with_options(
         LastfmTagStats::default()
     };
 
+    let musicbrainz_stats = if options.musicbrainz_tags {
+        log.info("Starting MusicBrainz tag backfill");
+        backfill_musicbrainz_tags(ctx, log, options.overwrite).await?
+    } else {
+        log.info("MusicBrainz tag backfill disabled for this run");
+        MusicBrainzTagStats::default()
+    };
+
     log.info(&format!(
-        "Metadata backfill complete: {scanned} scanned, {media_updated} media updated, {track_updated} tracks updated, {local_tags_updated} local tags saved, {unchanged} unchanged, {missing} missing, {failed} failed; Last.fm tags: considered={}, updated_entities={}, tags_saved={}, skipped_existing={}, not_found={}, failed={}",
+        "Metadata backfill complete: {scanned} scanned, {media_updated} media updated, {track_updated} tracks updated, {local_tags_updated} local tags saved, {unchanged} unchanged, {missing} missing, {failed} failed; Last.fm tags: considered={}, updated_entities={}, tags_saved={}, skipped_existing={}, not_found={}, failed={}; MusicBrainz tags: considered={}, updated_entities={}, tags_saved={}, skipped_existing={}, not_found={}, failed={}",
         lastfm_stats.considered,
         lastfm_stats.updated_entities,
         lastfm_stats.tags_saved,
         lastfm_stats.skipped_existing,
         lastfm_stats.not_found,
         lastfm_stats.failed,
+        musicbrainz_stats.considered,
+        musicbrainz_stats.updated_entities,
+        musicbrainz_stats.tags_saved,
+        musicbrainz_stats.skipped_existing,
+        musicbrainz_stats.not_found,
+        musicbrainz_stats.failed,
     ));
     Ok(())
 }
@@ -345,12 +375,277 @@ async fn backfill_lastfm_tags(
         .build()?;
 
     let mut stats = LastfmTagStats::default();
-    backfill_lastfm_artist_tags(ctx, log, &client, api_key, overwrite, &mut stats).await?;
-    backfill_lastfm_release_tags(ctx, log, &client, api_key, overwrite, &mut stats).await?;
-    backfill_lastfm_track_tags(ctx, log, &client, api_key, overwrite, &mut stats).await?;
+    if backfill_lastfm_artist_tags(ctx, log, &client, api_key, overwrite, &mut stats).await?
+        == LastfmTagPassResult::RateLimited
+    {
+        return Ok(stats);
+    }
+    if backfill_lastfm_release_tags(ctx, log, &client, api_key, overwrite, &mut stats).await?
+        == LastfmTagPassResult::RateLimited
+    {
+        return Ok(stats);
+    }
+    if backfill_lastfm_track_tags(ctx, log, &client, api_key, overwrite, &mut stats).await?
+        == LastfmTagPassResult::RateLimited
+    {
+        return Ok(stats);
+    }
     Ok(stats)
 }
 
+async fn backfill_musicbrainz_tags(
+    ctx: &JobContext,
+    log: &mut JobLog,
+    overwrite: bool,
+) -> anyhow::Result<MusicBrainzTagStats> {
+    log.info("MusicBrainz tag backfill started");
+    let client = crate::jobs::musicbrainz::MusicBrainzClient::new("furumusic-metadata-backfill")?;
+    let mut stats = MusicBrainzTagStats::default();
+    backfill_musicbrainz_artist_tags(ctx, log, &client, overwrite, &mut stats).await?;
+    backfill_musicbrainz_release_tags(ctx, log, &client, overwrite, &mut stats).await?;
+    Ok(stats)
+}
+
+async fn backfill_musicbrainz_artist_tags(
+    ctx: &JobContext,
+    log: &mut JobLog,
+    client: &crate::jobs::musicbrainz::MusicBrainzClient,
+    overwrite: bool,
+    stats: &mut MusicBrainzTagStats,
+) -> anyhow::Result<()> {
+    let rows = sqlx::query_as::<_, LastfmArtistTagRow>(
+        r#"SELECT DISTINCT a.id, a.name::text AS name
+           FROM furumusic__artist a
+           JOIN furumusic__track_artist ta ON ta.artist_id = a.id
+           JOIN furumusic__track t ON t.id = ta.track_id
+           WHERE a.is_hidden = false AND t.is_hidden = false
+           ORDER BY a.id"#,
+    )
+    .fetch_all(&ctx.pool)
+    .await?;
+
+    log.info(&format!(
+        "MusicBrainz artist tag pass: checking {} artist(s)",
+        rows.len()
+    ));
+    let total = rows.len();
+    for (index, row) in rows.into_iter().enumerate() {
+        if should_log_lastfm_item(index + 1, total, 25) {
+            log.info(&format!(
+                "MusicBrainz artist tags {}/{}: artist {} \"{}\"",
+                index + 1,
+                total,
+                row.id,
+                row.name
+            ));
+        }
+        if should_skip_source_entity(&ctx.pool, "artist", row.id, "musicbrainz", overwrite).await? {
+            stats.skipped_existing += 1;
+            continue;
+        }
+        stats.considered += 1;
+
+        let mbid =
+            match crate::jobs::musicbrainz::load_external_id(&ctx.pool, "artist", row.id, "artist")
+                .await?
+            {
+                Some(mbid) => Some(mbid),
+                None => match client.search_artist(&row.name).await {
+                    Ok(Some(found)) => {
+                        crate::jobs::musicbrainz::save_external_id(
+                            &ctx.pool,
+                            "artist",
+                            row.id,
+                            "artist",
+                            &found.mbid,
+                            found.score as f64 / 100.0,
+                        )
+                        .await?;
+                        Some(found.mbid)
+                    }
+                    Ok(None) => None,
+                    Err(err) => {
+                        stats.failed += 1;
+                        log.warn(&format!(
+                            "MusicBrainz artist search failed for artist {} \"{}\": {err}",
+                            row.id, row.name
+                        ));
+                        None
+                    }
+                },
+            };
+
+        let Some(mbid) = mbid else {
+            stats.not_found += 1;
+            continue;
+        };
+        match client.lookup_artist_tags(&mbid).await {
+            Ok(tags) if !tags.is_empty() => {
+                let tags = musicbrainz_tags_to_candidates(&tags);
+                match replace_entity_tags(&ctx.pool, "artist", row.id, &tags, "musicbrainz", false)
+                    .await
+                {
+                    Ok(saved) => {
+                        stats.tags_saved += saved;
+                        stats.updated_entities += 1;
+                    }
+                    Err(err) => {
+                        stats.failed += 1;
+                        log.warn(&format!(
+                            "MusicBrainz artist tags save failed for artist {} \"{}\": {err}",
+                            row.id, row.name
+                        ));
+                    }
+                }
+            }
+            Ok(_) => {
+                stats.not_found += 1;
+            }
+            Err(err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "MusicBrainz artist tags failed for artist {} \"{}\" mbid={}: {err}",
+                    row.id, row.name, mbid
+                ));
+            }
+        }
+    }
+    Ok(())
+}
+
+async fn backfill_musicbrainz_release_tags(
+    ctx: &JobContext,
+    log: &mut JobLog,
+    client: &crate::jobs::musicbrainz::MusicBrainzClient,
+    overwrite: bool,
+    stats: &mut MusicBrainzTagStats,
+) -> anyhow::Result<()> {
+    let rows = sqlx::query_as::<_, LastfmReleaseTagRow>(
+        r#"SELECT r.id,
+                  r.title::text AS title,
+                  (
+                    SELECT a.name::text
+                      FROM furumusic__release_artist ra
+                      JOIN furumusic__artist a ON a.id = ra.artist_id
+                     WHERE ra.release_id = r.id
+                     ORDER BY ra.position
+                     LIMIT 1
+                  ) AS artist_name,
+                  (
+                    SELECT t.title::text
+                      FROM furumusic__track t
+                     WHERE t.release_id = r.id
+                       AND t.is_hidden = false
+                     ORDER BY t.disc_number NULLS LAST, t.track_number NULLS LAST, t.id
+                     LIMIT 1
+                  ) AS track_title
+           FROM furumusic__release r
+           WHERE r.is_hidden = false
+           ORDER BY r.id"#,
+    )
+    .fetch_all(&ctx.pool)
+    .await?;
+
+    log.info(&format!(
+        "MusicBrainz release tag pass: checking {} release(s)",
+        rows.len()
+    ));
+    let total = rows.len();
+    for (index, row) in rows.into_iter().enumerate() {
+        if should_log_lastfm_item(index + 1, total, 25) {
+            log.info(&format!(
+                "MusicBrainz release tags {}/{}: release {} \"{}\"",
+                index + 1,
+                total,
+                row.id,
+                row.title
+            ));
+        }
+        if should_skip_source_entity(&ctx.pool, "release", row.id, "musicbrainz", overwrite).await?
+        {
+            stats.skipped_existing += 1;
+            continue;
+        }
+        let Some(artist) = row
+            .artist_name
+            .as_deref()
+            .filter(|value| !value.trim().is_empty())
+        else {
+            stats.not_found += 1;
+            continue;
+        };
+        stats.considered += 1;
+
+        let mbid = match crate::jobs::musicbrainz::load_or_search_release_mbid(
+            &ctx.pool,
+            client,
+            row.id,
+            artist,
+            &row.title,
+            row.track_title.as_deref(),
+        )
+        .await
+        {
+            Ok((release_mbid, _release_group_mbid)) => release_mbid,
+            Err(err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "MusicBrainz release search failed for release {} \"{}\" / \"{}\": {err}",
+                    row.id, artist, row.title
+                ));
+                None
+            }
+        };
+
+        let Some(mbid) = mbid else {
+            stats.not_found += 1;
+            continue;
+        };
+        match client.lookup_release_tags(&mbid).await {
+            Ok(result) if !result.tags.is_empty() => {
+                if let Some(group_mbid) = result.release_group_mbid.as_deref() {
+                    crate::jobs::musicbrainz::save_external_id(
+                        &ctx.pool,
+                        "release",
+                        row.id,
+                        "release_group",
+                        group_mbid,
+                        1.0,
+                    )
+                    .await?;
+                }
+                let tags = musicbrainz_tags_to_candidates(&result.tags);
+                match replace_entity_tags(&ctx.pool, "release", row.id, &tags, "musicbrainz", false)
+                    .await
+                {
+                    Ok(saved) => {
+                        stats.tags_saved += saved;
+                        stats.updated_entities += 1;
+                    }
+                    Err(err) => {
+                        stats.failed += 1;
+                        log.warn(&format!(
+                            "MusicBrainz release tags save failed for release {} \"{}\" / \"{}\": {err}",
+                            row.id, artist, row.title
+                        ));
+                    }
+                }
+            }
+            Ok(_) => {
+                stats.not_found += 1;
+            }
+            Err(err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "MusicBrainz release tags failed for release {} \"{}\" mbid={}: {err}",
+                    row.id, row.title, mbid
+                ));
+            }
+        }
+    }
+    Ok(())
+}
+
 async fn backfill_lastfm_artist_tags(
     ctx: &JobContext,
     log: &mut JobLog,
@@ -358,7 +653,7 @@ async fn backfill_lastfm_artist_tags(
     api_key: &str,
     overwrite: bool,
     stats: &mut LastfmTagStats,
-) -> anyhow::Result<()> {
+) -> anyhow::Result<LastfmTagPassResult> {
     let rows = sqlx::query_as::<_, LastfmArtistTagRow>(
         r#"SELECT DISTINCT a.id, a.name::text AS name
            FROM furumusic__artist a
@@ -376,31 +671,65 @@ async fn backfill_lastfm_artist_tags(
     ));
     let total = rows.len();
     for (index, row) in rows.into_iter().enumerate() {
-        if should_skip_lastfm_entity(&ctx.pool, "artist", row.id, overwrite).await? {
-            stats.skipped_existing += 1;
-            if should_log_lastfm_progress(index + 1, total, 25) {
-                log.info(&format!(
-                    "Last.fm artist tags progress: {}/{}",
-                    index + 1,
-                    total
+        if should_log_lastfm_item(index + 1, total, 25) {
+            log.info(&format!(
+                "Last.fm artist tags {}/{}: artist {} \"{}\"",
+                index + 1,
+                total,
+                row.id,
+                row.name
+            ));
+        }
+        match should_skip_lastfm_entity(&ctx.pool, "artist", row.id, overwrite).await {
+            Ok(true) => {
+                stats.skipped_existing += 1;
+                if should_log_lastfm_progress(index + 1, total, 25) {
+                    log.info(&format!(
+                        "Last.fm artist tags progress: {}/{}",
+                        index + 1,
+                        total
+                    ));
+                }
+                continue;
+            }
+            Ok(false) => {}
+            Err(err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "Last.fm artist tags skip check failed for artist {} \"{}\": {err}",
+                    row.id, row.name
                 ));
+                continue;
             }
-            continue;
         }
         stats.considered += 1;
         match fetch_lastfm_artist_tags(client, api_key, &row.name).await {
             Ok(tags) if !tags.is_empty() => {
-                let saved =
-                    replace_entity_tags(&ctx.pool, "artist", row.id, &tags, "lastfm", false)
-                        .await?;
-                stats.tags_saved += saved;
-                stats.updated_entities += 1;
+                match replace_entity_tags(&ctx.pool, "artist", row.id, &tags, "lastfm", false).await
+                {
+                    Ok(saved) => {
+                        stats.tags_saved += saved;
+                        stats.updated_entities += 1;
+                    }
+                    Err(err) => {
+                        stats.failed += 1;
+                        log.warn(&format!(
+                            "Last.fm artist tags save failed for artist {} \"{}\": {err}",
+                            row.id, row.name
+                        ));
+                    }
+                }
             }
             Ok(_) => {
                 stats.not_found += 1;
             }
-            Err(err) if err.to_string().contains("Last.fm rate limit exceeded") => {
-                return Err(err);
+            Err(err) if is_lastfm_rate_limit_error(&err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "Last.fm rate limit reached while fetching artist tags for artist {} \"{}\"; stopping Last.fm tag backfill for this run",
+                    row.id, row.name
+                ));
+                return Ok(LastfmTagPassResult::RateLimited);
             }
             Err(err) => {
                 stats.failed += 1;
@@ -419,7 +748,7 @@ async fn backfill_lastfm_artist_tags(
         }
         tokio::time::sleep(LASTFM_TAG_REQUEST_DELAY).await;
     }
-    Ok(())
+    Ok(LastfmTagPassResult::Completed)
 }
 
 async fn backfill_lastfm_release_tags(
@@ -429,7 +758,7 @@ async fn backfill_lastfm_release_tags(
     api_key: &str,
     overwrite: bool,
     stats: &mut LastfmTagStats,
-) -> anyhow::Result<()> {
+) -> anyhow::Result<LastfmTagPassResult> {
     let rows = sqlx::query_as::<_, LastfmReleaseTagRow>(
         r#"SELECT r.id,
                   r.title::text AS title,
@@ -440,7 +769,15 @@ async fn backfill_lastfm_release_tags(
                      WHERE ra.release_id = r.id
                      ORDER BY ra.position
                      LIMIT 1
-                  ) AS artist_name
+                  ) AS artist_name,
+                  (
+                    SELECT t.title::text
+                      FROM furumusic__track t
+                     WHERE t.release_id = r.id
+                       AND t.is_hidden = false
+                     ORDER BY t.disc_number NULLS LAST, t.track_number NULLS LAST, t.id
+                     LIMIT 1
+                  ) AS track_title
            FROM furumusic__release r
            WHERE r.is_hidden = false
            ORDER BY r.id"#,
@@ -454,18 +791,41 @@ async fn backfill_lastfm_release_tags(
     ));
     let total = rows.len();
     for (index, row) in rows.into_iter().enumerate() {
-        if should_skip_lastfm_entity(&ctx.pool, "release", row.id, overwrite).await? {
-            stats.skipped_existing += 1;
-            if should_log_lastfm_progress(index + 1, total, 25) {
-                log.info(&format!(
-                    "Last.fm release tags progress: {}/{}",
-                    index + 1,
-                    total
-                ));
-            }
-            continue;
+        if should_log_lastfm_item(index + 1, total, 25) {
+            log.info(&format!(
+                "Last.fm release tags {}/{}: release {} \"{}\"",
+                index + 1,
+                total,
+                row.id,
+                row.title
+            ));
         }
-        let Some(artist) = row.artist_name.as_deref().filter(|value| !value.trim().is_empty())
+        match should_skip_lastfm_entity(&ctx.pool, "release", row.id, overwrite).await {
+            Ok(true) => {
+                stats.skipped_existing += 1;
+                if should_log_lastfm_progress(index + 1, total, 25) {
+                    log.info(&format!(
+                        "Last.fm release tags progress: {}/{}",
+                        index + 1,
+                        total
+                    ));
+                }
+                continue;
+            }
+            Ok(false) => {}
+            Err(err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "Last.fm release tags skip check failed for release {} \"{}\": {err}",
+                    row.id, row.title
+                ));
+                continue;
+            }
+        }
+        let Some(artist) = row
+            .artist_name
+            .as_deref()
+            .filter(|value| !value.trim().is_empty())
         else {
             stats.not_found += 1;
             if should_log_lastfm_progress(index + 1, total, 25) {
@@ -480,17 +840,32 @@ async fn backfill_lastfm_release_tags(
         stats.considered += 1;
         match fetch_lastfm_album_tags(client, api_key, artist, &row.title).await {
             Ok(tags) if !tags.is_empty() => {
-                let saved =
-                    replace_entity_tags(&ctx.pool, "release", row.id, &tags, "lastfm", false)
-                        .await?;
-                stats.tags_saved += saved;
-                stats.updated_entities += 1;
+                match replace_entity_tags(&ctx.pool, "release", row.id, &tags, "lastfm", false)
+                    .await
+                {
+                    Ok(saved) => {
+                        stats.tags_saved += saved;
+                        stats.updated_entities += 1;
+                    }
+                    Err(err) => {
+                        stats.failed += 1;
+                        log.warn(&format!(
+                            "Last.fm release tags save failed for release {} \"{}\" / \"{}\": {err}",
+                            row.id, artist, row.title
+                        ));
+                    }
+                }
             }
             Ok(_) => {
                 stats.not_found += 1;
             }
-            Err(err) if err.to_string().contains("Last.fm rate limit exceeded") => {
-                return Err(err);
+            Err(err) if is_lastfm_rate_limit_error(&err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "Last.fm rate limit reached while fetching release tags for release {} \"{}\" / \"{}\"; stopping Last.fm tag backfill for this run",
+                    row.id, artist, row.title
+                ));
+                return Ok(LastfmTagPassResult::RateLimited);
             }
             Err(err) => {
                 stats.failed += 1;
@@ -509,7 +884,7 @@ async fn backfill_lastfm_release_tags(
         }
         tokio::time::sleep(LASTFM_TAG_REQUEST_DELAY).await;
     }
-    Ok(())
+    Ok(LastfmTagPassResult::Completed)
 }
 
 async fn backfill_lastfm_track_tags(
@@ -519,7 +894,7 @@ async fn backfill_lastfm_track_tags(
     api_key: &str,
     overwrite: bool,
     stats: &mut LastfmTagStats,
-) -> anyhow::Result<()> {
+) -> anyhow::Result<LastfmTagPassResult> {
     let rows = sqlx::query_as::<_, LastfmTrackTagRow>(
         r#"SELECT t.id,
                   t.title::text AS title,
@@ -544,18 +919,41 @@ async fn backfill_lastfm_track_tags(
     ));
     let total = rows.len();
     for (index, row) in rows.into_iter().enumerate() {
-        if should_skip_lastfm_entity(&ctx.pool, "track", row.id, overwrite).await? {
-            stats.skipped_existing += 1;
-            if should_log_lastfm_progress(index + 1, total, 50) {
-                log.info(&format!(
-                    "Last.fm track tags progress: {}/{}",
-                    index + 1,
-                    total
-                ));
-            }
-            continue;
+        if should_log_lastfm_item(index + 1, total, 50) {
+            log.info(&format!(
+                "Last.fm track tags {}/{}: track {} \"{}\"",
+                index + 1,
+                total,
+                row.id,
+                row.title
+            ));
         }
-        let Some(artist) = row.artist_name.as_deref().filter(|value| !value.trim().is_empty())
+        match should_skip_lastfm_entity(&ctx.pool, "track", row.id, overwrite).await {
+            Ok(true) => {
+                stats.skipped_existing += 1;
+                if should_log_lastfm_progress(index + 1, total, 50) {
+                    log.info(&format!(
+                        "Last.fm track tags progress: {}/{}",
+                        index + 1,
+                        total
+                    ));
+                }
+                continue;
+            }
+            Ok(false) => {}
+            Err(err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "Last.fm track tags skip check failed for track {} \"{}\": {err}",
+                    row.id, row.title
+                ));
+                continue;
+            }
+        }
+        let Some(artist) = row
+            .artist_name
+            .as_deref()
+            .filter(|value| !value.trim().is_empty())
         else {
             stats.not_found += 1;
             if should_log_lastfm_progress(index + 1, total, 50) {
@@ -570,16 +968,30 @@ async fn backfill_lastfm_track_tags(
         stats.considered += 1;
         match fetch_lastfm_track_tags(client, api_key, artist, &row.title).await {
             Ok(tags) if !tags.is_empty() => {
-                let saved =
-                    replace_entity_tags(&ctx.pool, "track", row.id, &tags, "lastfm", true).await?;
-                stats.tags_saved += saved;
-                stats.updated_entities += 1;
+                match replace_entity_tags(&ctx.pool, "track", row.id, &tags, "lastfm", true).await {
+                    Ok(saved) => {
+                        stats.tags_saved += saved;
+                        stats.updated_entities += 1;
+                    }
+                    Err(err) => {
+                        stats.failed += 1;
+                        log.warn(&format!(
+                            "Last.fm track tags save failed for track {} \"{}\" / \"{}\": {err}",
+                            row.id, artist, row.title
+                        ));
+                    }
+                }
             }
             Ok(_) => {
                 stats.not_found += 1;
             }
-            Err(err) if err.to_string().contains("Last.fm rate limit exceeded") => {
-                return Err(err);
+            Err(err) if is_lastfm_rate_limit_error(&err) => {
+                stats.failed += 1;
+                log.warn(&format!(
+                    "Last.fm rate limit reached while fetching track tags for track {} \"{}\" / \"{}\"; stopping Last.fm tag backfill for this run",
+                    row.id, artist, row.title
+                ));
+                return Ok(LastfmTagPassResult::RateLimited);
             }
             Err(err) => {
                 stats.failed += 1;
@@ -598,18 +1010,36 @@ async fn backfill_lastfm_track_tags(
         }
         tokio::time::sleep(LASTFM_TAG_REQUEST_DELAY).await;
     }
-    Ok(())
+    Ok(LastfmTagPassResult::Completed)
 }
 
 fn should_log_lastfm_progress(done: usize, total: usize, every: usize) -> bool {
     total > 0 && (done == total || done % every == 0)
 }
 
+fn should_log_lastfm_item(done: usize, total: usize, every: usize) -> bool {
+    total > 0 && (done == 1 || done == total || done % every == 0)
+}
+
+fn is_lastfm_rate_limit_error(err: &anyhow::Error) -> bool {
+    err.to_string().contains("Last.fm rate limit exceeded")
+}
+
 async fn should_skip_lastfm_entity(
     pool: &sqlx::PgPool,
     entity_kind: &str,
     entity_id: i64,
     overwrite: bool,
+) -> anyhow::Result<bool> {
+    should_skip_source_entity(pool, entity_kind, entity_id, "lastfm", overwrite).await
+}
+
+async fn should_skip_source_entity(
+    pool: &sqlx::PgPool,
+    entity_kind: &str,
+    entity_id: i64,
+    source: &str,
+    overwrite: bool,
 ) -> anyhow::Result<bool> {
     if overwrite {
         return Ok(false);
@@ -617,16 +1047,28 @@ async fn should_skip_lastfm_entity(
     let exists: Option<i64> = sqlx::query_scalar(
         r#"SELECT 1
            FROM furumusic__entity_genre_tag
-           WHERE entity_kind = $1 AND entity_id = $2 AND source = 'lastfm'
+           WHERE entity_kind = $1 AND entity_id = $2 AND source = $3
            LIMIT 1"#,
     )
     .bind(entity_kind)
     .bind(entity_id)
+    .bind(source)
     .fetch_optional(pool)
     .await?;
     Ok(exists.is_some())
 }
 
+fn musicbrainz_tags_to_candidates(
+    tags: &[crate::jobs::musicbrainz::MusicBrainzTag],
+) -> Vec<TagCandidate> {
+    tags.iter()
+        .map(|tag| TagCandidate {
+            name: tag.name.clone(),
+            weight: tag.weight,
+        })
+        .collect()
+}
+
 async fn fetch_lastfm_artist_tags(
     client: &reqwest::Client,
     api_key: &str,
@@ -723,7 +1165,11 @@ async fn fetch_lastfm_top_tags(
         Value::Object(_) => tag_from_value(tag_value).into_iter().collect::<Vec<_>>(),
         _ => Vec::new(),
     };
-    tags.sort_by(|a, b| b.weight.total_cmp(&a.weight).then_with(|| a.name.cmp(&b.name)));
+    tags.sort_by(|a, b| {
+        b.weight
+            .total_cmp(&a.weight)
+            .then_with(|| a.name.cmp(&b.name))
+    });
     tags.truncate(LASTFM_TAG_LIMIT);
     Ok(tags)
 }
@@ -896,9 +1342,9 @@ fn tags_from_text(value: &str) -> Vec<TagCandidate> {
     for raw in normalized_separators.split([';', ',']) {
         if let Some(name) = clean_tag_name(raw) {
             if !is_ignored_tag(&normalize_tag_name(&name))
-                && !tags
-                    .iter()
-                    .any(|tag: &TagCandidate| normalize_tag_name(&tag.name) == normalize_tag_name(&name))
+                && !tags.iter().any(|tag: &TagCandidate| {
+                    normalize_tag_name(&tag.name) == normalize_tag_name(&name)
+                })
             {
                 tags.push(TagCandidate { name, weight: 1.0 });
             }

src/jobs/mod.rs

@@ -1,9 +1,11 @@
+pub mod archive_cleanup;
 pub mod artwork_backfill;
 pub mod inbox_discover;
 pub mod inbox_process;
 pub mod lastfm_popularity;
 pub mod lastfm_scrobble;
 pub mod metadata_backfill;
+pub mod musicbrainz;
 
 use std::path::{Component, Path, PathBuf};
 

src/jobs/musicbrainz.rs

@@ -0,0 +1,587 @@
+use std::time::{Duration, Instant};
+
+use reqwest::{Client, StatusCode};
+use serde::Deserialize;
+use tokio::sync::Mutex;
+
+const MUSICBRAINZ_BASE_URL: &str = "https://musicbrainz.org/ws/2";
+const COVER_ART_ARCHIVE_BASE_URL: &str = "https://coverartarchive.org";
+const MUSICBRAINZ_REQUEST_DELAY: Duration = Duration::from_millis(1100);
+const MUSICBRAINZ_TAG_LIMIT: usize = 12;
+
+#[derive(Debug, Clone)]
+pub struct MusicBrainzTag {
+    pub name: String,
+    pub weight: f64,
+}
+
+#[derive(Debug, Clone)]
+pub struct MusicBrainzArtistMatch {
+    pub mbid: String,
+    pub score: i32,
+}
+
+#[derive(Debug, Clone)]
+pub struct MusicBrainzReleaseMatch {
+    pub mbid: String,
+    pub release_group_mbid: Option<String>,
+    pub score: i32,
+}
+
+#[derive(Debug, Clone)]
+pub struct MusicBrainzReleaseTags {
+    pub release_group_mbid: Option<String>,
+    pub tags: Vec<MusicBrainzTag>,
+}
+
+pub struct MusicBrainzClient {
+    client: Client,
+    last_musicbrainz_request: Mutex<Option<Instant>>,
+}
+
+pub async fn load_external_id(
+    pool: &sqlx::PgPool,
+    entity_kind: &str,
+    entity_id: i64,
+    id_kind: &str,
+) -> anyhow::Result<Option<String>> {
+    let value = sqlx::query_scalar::<_, String>(
+        r#"SELECT external_id::text
+           FROM furumusic__external_metadata_id
+           WHERE entity_kind = $1
+             AND entity_id = $2
+             AND source = 'musicbrainz'
+             AND id_kind = $3
+           LIMIT 1"#,
+    )
+    .bind(entity_kind)
+    .bind(entity_id)
+    .bind(id_kind)
+    .fetch_optional(pool)
+    .await?;
+    Ok(value)
+}
+
+pub async fn save_external_id(
+    pool: &sqlx::PgPool,
+    entity_kind: &str,
+    entity_id: i64,
+    id_kind: &str,
+    external_id: &str,
+    confidence: f64,
+) -> anyhow::Result<()> {
+    sqlx::query(
+        r#"INSERT INTO furumusic__external_metadata_id
+              (entity_kind, entity_id, source, id_kind, external_id, confidence, updated_at)
+           VALUES ($1, $2, 'musicbrainz', $3, $4, $5, $6)
+           ON CONFLICT (entity_kind, entity_id, source, id_kind) DO UPDATE SET
+              external_id = EXCLUDED.external_id,
+              confidence = EXCLUDED.confidence,
+              updated_at = EXCLUDED.updated_at"#,
+    )
+    .bind(entity_kind)
+    .bind(entity_id)
+    .bind(id_kind)
+    .bind(external_id)
+    .bind(confidence)
+    .bind(now_iso())
+    .execute(pool)
+    .await?;
+    Ok(())
+}
+
+pub async fn load_or_search_release_mbid(
+    pool: &sqlx::PgPool,
+    client: &MusicBrainzClient,
+    release_id: i64,
+    artist_name: &str,
+    release_title: &str,
+    representative_track_title: Option<&str>,
+) -> anyhow::Result<(Option<String>, Option<String>)> {
+    let release_mbid = load_external_id(pool, "release", release_id, "release").await?;
+    let release_group_mbid = load_external_id(pool, "release", release_id, "release_group").await?;
+    if release_mbid.is_some() || release_group_mbid.is_some() {
+        return Ok((release_mbid, release_group_mbid));
+    }
+
+    let found = match client.search_release(artist_name, release_title).await? {
+        Some(found) => Some(found),
+        None => {
+            if let Some(track_title) =
+                representative_track_title.filter(|value| !value.trim().is_empty())
+            {
+                client
+                    .search_release_by_recording(artist_name, track_title)
+                    .await?
+            } else {
+                None
+            }
+        }
+    };
+
+    let Some(found) = found else {
+        return Ok((None, None));
+    };
+    save_external_id(
+        pool,
+        "release",
+        release_id,
+        "release",
+        &found.mbid,
+        found.score as f64 / 100.0,
+    )
+    .await?;
+    if let Some(group_mbid) = found.release_group_mbid.as_deref() {
+        save_external_id(
+            pool,
+            "release",
+            release_id,
+            "release_group",
+            group_mbid,
+            found.score as f64 / 100.0,
+        )
+        .await?;
+    }
+    Ok((Some(found.mbid), found.release_group_mbid))
+}
+
+impl MusicBrainzClient {
+    pub fn new(user_agent_prefix: &str) -> anyhow::Result<Self> {
+        let client = Client::builder()
+            .user_agent(format!(
+                "{}/{} (musicbrainz.org/doc/MusicBrainz_API)",
+                user_agent_prefix,
+                env!("CARGO_PKG_VERSION")
+            ))
+            .timeout(Duration::from_secs(20))
+            .build()?;
+        Ok(Self {
+            client,
+            last_musicbrainz_request: Mutex::new(None),
+        })
+    }
+
+    pub fn http_client(&self) -> &Client {
+        &self.client
+    }
+
+    pub async fn search_artist(
+        &self,
+        name: &str,
+    ) -> anyhow::Result<Option<MusicBrainzArtistMatch>> {
+        let query = format!("artist:\"{}\"", escape_search_value(name));
+        let response: Option<ArtistSearchResponse> = self
+            .get_musicbrainz_json(
+                "artist",
+                &[("query", query.as_str()), ("fmt", "json"), ("limit", "5")],
+            )
+            .await?;
+        let Some(response) = response else {
+            return Ok(None);
+        };
+        Ok(response
+            .artists
+            .into_iter()
+            .filter(|artist| artist.id.trim().len() == 36)
+            .max_by_key(|artist| artist.score.unwrap_or(0))
+            .and_then(|artist| {
+                let score = artist.score.unwrap_or(0);
+                (score >= 70).then_some(MusicBrainzArtistMatch {
+                    mbid: artist.id,
+                    score,
+                })
+            }))
+    }
+
+    pub async fn search_release(
+        &self,
+        artist: &str,
+        title: &str,
+    ) -> anyhow::Result<Option<MusicBrainzReleaseMatch>> {
+        let query = format!(
+            "release:\"{}\" AND artist:\"{}\"",
+            escape_search_value(title),
+            escape_search_value(artist)
+        );
+        let response: Option<ReleaseSearchResponse> = self
+            .get_musicbrainz_json(
+                "release",
+                &[("query", query.as_str()), ("fmt", "json"), ("limit", "5")],
+            )
+            .await?;
+        let Some(response) = response else {
+            return Ok(None);
+        };
+        Ok(response
+            .releases
+            .into_iter()
+            .filter(|release| release.id.trim().len() == 36)
+            .max_by_key(|release| release.score.unwrap_or(0))
+            .and_then(|release| {
+                let score = release.score.unwrap_or(0);
+                (score >= 70).then_some(MusicBrainzReleaseMatch {
+                    mbid: release.id,
+                    release_group_mbid: release.release_group.map(|group| group.id),
+                    score,
+                })
+            }))
+    }
+
+    pub async fn search_release_by_recording(
+        &self,
+        artist: &str,
+        track_title: &str,
+    ) -> anyhow::Result<Option<MusicBrainzReleaseMatch>> {
+        let query = format!(
+            "recording:\"{}\" AND artist:\"{}\"",
+            escape_search_value(track_title),
+            escape_search_value(artist)
+        );
+        let response: Option<RecordingSearchResponse> = self
+            .get_musicbrainz_json(
+                "recording",
+                &[("query", query.as_str()), ("fmt", "json"), ("limit", "5")],
+            )
+            .await?;
+        let Some(response) = response else {
+            return Ok(None);
+        };
+
+        Ok(response
+            .recordings
+            .into_iter()
+            .flat_map(|recording| {
+                let recording_score = recording.score.unwrap_or(0);
+                recording
+                    .releases
+                    .into_iter()
+                    .filter(move |release| release.id.trim().len() == 36)
+                    .map(move |release| (recording_score, release))
+            })
+            .max_by_key(|(score, _)| *score)
+            .and_then(|(score, release)| {
+                (score >= 70).then_some(MusicBrainzReleaseMatch {
+                    mbid: release.id,
+                    release_group_mbid: release.release_group.map(|group| group.id),
+                    score,
+                })
+            }))
+    }
+
+    pub async fn lookup_artist_tags(&self, mbid: &str) -> anyhow::Result<Vec<MusicBrainzTag>> {
+        let response: Option<TaggedEntityResponse> = self
+            .get_musicbrainz_json(
+                &format!("artist/{mbid}"),
+                &[("inc", "tags+genres"), ("fmt", "json")],
+            )
+            .await?;
+        Ok(response.map(tags_from_entity).unwrap_or_default())
+    }
+
+    pub async fn lookup_release_tags(&self, mbid: &str) -> anyhow::Result<MusicBrainzReleaseTags> {
+        let response: Option<ReleaseLookupResponse> = self
+            .get_musicbrainz_json(
+                &format!("release/{mbid}"),
+                &[("inc", "tags+genres+release-groups"), ("fmt", "json")],
+            )
+            .await?;
+        let Some(response) = response else {
+            return Ok(MusicBrainzReleaseTags {
+                release_group_mbid: None,
+                tags: Vec::new(),
+            });
+        };
+
+        let mut tags = tags_from_parts(response.tags, response.genres);
+        let release_group_mbid = response
+            .release_group
+            .as_ref()
+            .map(|group| group.id.clone());
+        if let Some(group_mbid) = release_group_mbid.as_deref() {
+            let group_response: Option<TaggedEntityResponse> = self
+                .get_musicbrainz_json(
+                    &format!("release-group/{group_mbid}"),
+                    &[("inc", "tags+genres"), ("fmt", "json")],
+                )
+                .await?;
+            merge_tags(
+                &mut tags,
+                group_response.map(tags_from_entity).unwrap_or_default(),
+            );
+        }
+        tags.sort_by(|a, b| {
+            b.weight
+                .total_cmp(&a.weight)
+                .then_with(|| a.name.cmp(&b.name))
+        });
+        tags.truncate(MUSICBRAINZ_TAG_LIMIT);
+
+        Ok(MusicBrainzReleaseTags {
+            release_group_mbid,
+            tags,
+        })
+    }
+
+    pub async fn fetch_cover_art_front_url(
+        &self,
+        release_mbid: Option<&str>,
+        release_group_mbid: Option<&str>,
+    ) -> anyhow::Result<Option<String>> {
+        if let Some(mbid) = release_mbid {
+            if let Some(url) = self.cover_art_front_url("release", mbid).await? {
+                return Ok(Some(url));
+            }
+        }
+        if let Some(mbid) = release_group_mbid {
+            if let Some(url) = self.cover_art_front_url("release-group", mbid).await? {
+                return Ok(Some(url));
+            }
+        }
+        Ok(None)
+    }
+
+    async fn get_musicbrainz_json<T>(
+        &self,
+        path: &str,
+        query: &[(&str, &str)],
+    ) -> anyhow::Result<Option<T>>
+    where
+        T: for<'de> Deserialize<'de>,
+    {
+        self.wait_for_musicbrainz_slot().await;
+        let url = format!("{MUSICBRAINZ_BASE_URL}/{}", path.trim_start_matches('/'));
+        let response = self.client.get(url).query(query).send().await?;
+        if response.status() == StatusCode::NOT_FOUND {
+            return Ok(None);
+        }
+        if response.status() == StatusCode::TOO_MANY_REQUESTS
+            || response.status() == StatusCode::SERVICE_UNAVAILABLE
+        {
+            anyhow::bail!(
+                "MusicBrainz rate limit or service unavailable: {}",
+                response.status()
+            );
+        }
+        let response = response.error_for_status()?;
+        Ok(Some(response.json::<T>().await?))
+    }
+
+    async fn cover_art_front_url(&self, kind: &str, mbid: &str) -> anyhow::Result<Option<String>> {
+        let url = format!("{COVER_ART_ARCHIVE_BASE_URL}/{kind}/{mbid}");
+        let response = self.client.get(url).send().await?;
+        if response.status() == StatusCode::NOT_FOUND {
+            return Ok(None);
+        }
+        if response.status() == StatusCode::TOO_MANY_REQUESTS
+            || response.status() == StatusCode::SERVICE_UNAVAILABLE
+        {
+            anyhow::bail!("Cover Art Archive unavailable: {}", response.status());
+        }
+        let response = response.error_for_status()?;
+        let body = response.json::<CoverArtArchiveResponse>().await?;
+        Ok(best_cover_art_url(body.images))
+    }
+
+    async fn wait_for_musicbrainz_slot(&self) {
+        let mut last = self.last_musicbrainz_request.lock().await;
+        if let Some(previous) = *last {
+            let elapsed = previous.elapsed();
+            if elapsed < MUSICBRAINZ_REQUEST_DELAY {
+                tokio::time::sleep(MUSICBRAINZ_REQUEST_DELAY - elapsed).await;
+            }
+        }
+        *last = Some(Instant::now());
+    }
+}
+
+fn now_iso() -> String {
+    chrono::Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string()
+}
+
+#[derive(Debug, Deserialize)]
+struct ArtistSearchResponse {
+    #[serde(default)]
+    artists: Vec<ArtistSearchItem>,
+}
+
+#[derive(Debug, Deserialize)]
+struct ArtistSearchItem {
+    id: String,
+    score: Option<i32>,
+}
+
+#[derive(Debug, Deserialize)]
+struct ReleaseSearchResponse {
+    #[serde(default)]
+    releases: Vec<ReleaseSearchItem>,
+}
+
+#[derive(Debug, Deserialize)]
+struct ReleaseSearchItem {
+    id: String,
+    score: Option<i32>,
+    #[serde(rename = "release-group")]
+    release_group: Option<MusicBrainzIdRef>,
+}
+
+#[derive(Debug, Deserialize)]
+struct RecordingSearchResponse {
+    #[serde(default)]
+    recordings: Vec<RecordingSearchItem>,
+}
+
+#[derive(Debug, Deserialize)]
+struct RecordingSearchItem {
+    score: Option<i32>,
+    #[serde(default)]
+    releases: Vec<RecordingReleaseItem>,
+}
+
+#[derive(Debug, Deserialize)]
+struct RecordingReleaseItem {
+    id: String,
+    #[serde(rename = "release-group")]
+    release_group: Option<MusicBrainzIdRef>,
+}
+
+#[derive(Debug, Deserialize)]
+struct ReleaseLookupResponse {
+    #[serde(default)]
+    tags: Vec<MusicBrainzTagItem>,
+    #[serde(default)]
+    genres: Vec<MusicBrainzTagItem>,
+    #[serde(rename = "release-group")]
+    release_group: Option<MusicBrainzIdRef>,
+}
+
+#[derive(Debug, Deserialize)]
+struct TaggedEntityResponse {
+    #[serde(default)]
+    tags: Vec<MusicBrainzTagItem>,
+    #[serde(default)]
+    genres: Vec<MusicBrainzTagItem>,
+}
+
+#[derive(Debug, Deserialize)]
+struct MusicBrainzIdRef {
+    id: String,
+}
+
+#[derive(Debug, Deserialize)]
+struct MusicBrainzTagItem {
+    name: String,
+    count: Option<i64>,
+}
+
+#[derive(Debug, Deserialize)]
+struct CoverArtArchiveResponse {
+    #[serde(default)]
+    images: Vec<CoverArtArchiveImage>,
+}
+
+#[derive(Debug, Deserialize)]
+struct CoverArtArchiveImage {
+    image: Option<String>,
+    front: Option<bool>,
+    approved: Option<bool>,
+    #[serde(default)]
+    types: Vec<String>,
+    thumbnails: Option<CoverArtArchiveThumbnails>,
+}
+
+#[derive(Debug, Deserialize)]
+struct CoverArtArchiveThumbnails {
+    #[serde(rename = "1200")]
+    size_1200: Option<String>,
+    #[serde(rename = "500")]
+    size_500: Option<String>,
+    large: Option<String>,
+}
+
+fn escape_search_value(value: &str) -> String {
+    value.replace('\\', "\\\\").replace('"', "\\\"")
+}
+
+fn tags_from_entity(entity: TaggedEntityResponse) -> Vec<MusicBrainzTag> {
+    tags_from_parts(entity.tags, entity.genres)
+}
+
+fn tags_from_parts(
+    tags: Vec<MusicBrainzTagItem>,
+    genres: Vec<MusicBrainzTagItem>,
+) -> Vec<MusicBrainzTag> {
+    let mut result = Vec::new();
+    merge_items(&mut result, genres, 2.0);
+    merge_items(&mut result, tags, 1.0);
+    result.sort_by(|a, b| {
+        b.weight
+            .total_cmp(&a.weight)
+            .then_with(|| a.name.cmp(&b.name))
+    });
+    result.truncate(MUSICBRAINZ_TAG_LIMIT);
+    result
+}
+
+fn merge_items(result: &mut Vec<MusicBrainzTag>, items: Vec<MusicBrainzTagItem>, multiplier: f64) {
+    for item in items {
+        let name = item.name.trim();
+        if name.is_empty() {
+            continue;
+        }
+        let weight = item.count.unwrap_or(1).max(1) as f64 * multiplier;
+        if let Some(existing) = result
+            .iter_mut()
+            .find(|tag| tag.name.eq_ignore_ascii_case(name))
+        {
+            existing.weight = existing.weight.max(weight);
+        } else {
+            result.push(MusicBrainzTag {
+                name: name.to_string(),
+                weight,
+            });
+        }
+    }
+}
+
+fn merge_tags(result: &mut Vec<MusicBrainzTag>, extra: Vec<MusicBrainzTag>) {
+    for tag in extra {
+        if let Some(existing) = result
+            .iter_mut()
+            .find(|candidate| candidate.name.eq_ignore_ascii_case(&tag.name))
+        {
+            existing.weight = existing.weight.max(tag.weight);
+        } else {
+            result.push(tag);
+        }
+    }
+}
+
+fn best_cover_art_url(mut images: Vec<CoverArtArchiveImage>) -> Option<String> {
+    images.sort_by_key(|image| {
+        let front = image.front.unwrap_or(false)
+            || image
+                .types
+                .iter()
+                .any(|value| value.eq_ignore_ascii_case("front"));
+        let approved = image.approved.unwrap_or(false);
+        (u8::from(front), u8::from(approved))
+    });
+    images
+        .into_iter()
+        .rev()
+        .find_map(|image| {
+            image
+                .thumbnails
+                .as_ref()
+                .and_then(|thumbs| {
+                    thumbs
+                        .size_1200
+                        .as_deref()
+                        .or(thumbs.size_500.as_deref())
+                        .or(thumbs.large.as_deref())
+                })
+                .map(str::to_string)
+                .or(image.image)
+        })
+        .filter(|url| !url.trim().is_empty())
+}

src/lastfm.rs

@@ -447,17 +447,17 @@ async fn fetch_pending_scrobbles(
                   o.duration_seconds,
                   o.attempt_count,
                   a.session_key::text AS session_key,
-                  t.title::text AS title,
-                  r.title::text AS album_title,
+                  COALESCE(o.track_title, t.title::text) AS title,
+                  COALESCE(o.album_title, r.title::text) AS album_title,
                   t.track_number,
-                  (
+                  COALESCE(o.artist_name, (
                     SELECT ar.name::text
                       FROM furumusic__track_artist ta
                       JOIN furumusic__artist ar ON ar.id = ta.artist_id
                      WHERE ta.track_id = t.id AND ta.role <> 'featuring'
                      ORDER BY ta.position
                      LIMIT 1
-                  ) AS artist_name,
+                  )) AS artist_name,
                   (
                     SELECT ar.name::text
                       FROM furumusic__release_artist ra
@@ -468,7 +468,7 @@ async fn fetch_pending_scrobbles(
                   ) AS album_artist_name
              FROM furumusic__lastfm_scrobble_outbox o
              JOIN furumusic__lastfm_account a ON a.user_id = o.user_id
-             JOIN furumusic__track t ON t.id = o.track_id
+             LEFT JOIN furumusic__track t ON t.id = o.track_id
              LEFT JOIN furumusic__release r ON r.id = t.release_id
             WHERE o.user_id = $1
               AND o.status IN ('pending', 'retry')

src/main.rs

@@ -3,10 +3,12 @@ mod agent;
 mod api;
 mod auth;
 mod config;
+mod federation;
 mod i18n;
 mod jobs;
 mod lastfm;
 mod media_paths;
+mod metrics;
 mod music;
 mod oidc;
 mod player;
@@ -28,7 +30,7 @@ use cot::form::{Form, FormResult};
 use cot::html::Html;
 use cot::middleware::SessionMiddleware;
 use cot::project::RegisterAppsContext;
-use cot::request::extractors::{RequestForm, UrlQuery};
+use cot::request::extractors::{Path, RequestForm, UrlQuery};
 use cot::response::IntoResponse;
 use cot::router::method::get;
 use cot::router::{Route, Router};
@@ -51,6 +53,7 @@ fn build_registry() -> Arc<JobRegistry> {
     registry.register(jobs::inbox_discover::InboxDiscoverJob);
     registry.register(jobs::inbox_process::InboxProcessJob);
     registry.register(jobs::inbox_process::FileProcessJob);
+    registry.register(jobs::archive_cleanup::ArchiveCleanupJob);
     registry.register(jobs::artwork_backfill::ArtworkBackfillJob);
     registry.register(jobs::metadata_backfill::MetadataBackfillJob);
     registry.register(jobs::lastfm_popularity::LastfmPopularityJob);
@@ -62,15 +65,55 @@ fn build_registry() -> Arc<JobRegistry> {
 // Handlers
 // ---------------------------------------------------------------------------
 
-async fn index(session: Session, db: Database, i18n: I18n) -> cot::Result<cot::response::Response> {
+#[derive(Deserialize)]
+struct IndexQuery {
+    track: Option<i64>,
+    release: Option<i64>,
+    playlist_share: Option<String>,
+}
+
+async fn index(
+    session: Session,
+    db: Database,
+    i18n: I18n,
+    UrlQuery(query): UrlQuery<IndexQuery>,
+) -> cot::Result<cot::response::Response> {
     let _user = match auth::get_session_user(&session, &db).await {
         Some(u) => u,
-        None => return Ok(auth::redirect("/login")),
+        None => {
+            if let Some(location) = share_query_redirect(&query) {
+                auth::remember_post_login_redirect(&session, &location).await?;
+            }
+            return Ok(auth::redirect("/login"));
+        }
     };
     let template = player::PlayerPageTemplate { t: i18n.t };
     Html::new(template.render()?).into_response()
 }
 
+fn share_query_redirect(query: &IndexQuery) -> Option<String> {
+    if let Some(track_id) = query.track.filter(|id| *id > 0) {
+        return Some(format!("/?track={track_id}"));
+    }
+    if let Some(release_id) = query.release.filter(|id| *id > 0) {
+        return Some(format!("/?release={release_id}"));
+    }
+    let token = query.playlist_share.as_deref()?.trim();
+    if is_share_token(token) {
+        Some(format!("/?playlist_share={token}"))
+    } else {
+        None
+    }
+}
+
+fn is_share_token(token: &str) -> bool {
+    !token.is_empty()
+        && token.len() <= 64
+        && token
+            .bytes()
+            .all(|b| b.is_ascii_alphanumeric() || matches!(b, b'-' | b'_'))
+}
+
 #[derive(Deserialize)]
 struct SetLangQuery {
     lang: String,
@@ -130,6 +173,21 @@ struct LoginForm {
     password: String,
 }
 
+#[derive(Deserialize)]
+struct LoginQuery {
+    error: Option<String>,
+}
+
+#[derive(Deserialize)]
+struct SharePathId {
+    id: i64,
+}
+
+#[derive(Deserialize)]
+struct SharePathToken {
+    token: String,
+}
+
 // ---------------------------------------------------------------------------
 // Logout
 // ---------------------------------------------------------------------------
@@ -139,12 +197,93 @@ async fn logout_handler(session: Session) -> cot::Result<cot::response::Response
     Ok(auth::redirect("/login"))
 }
 
+async fn metrics_handler(
+    config: Arc<AppConfig>,
+    pool: Arc<tokio::sync::OnceCell<sqlx::PgPool>>,
+) -> cot::Result<cot::http::Response<Body>> {
+    if config.database_url.is_empty() {
+        return Ok(cot::http::Response::builder()
+            .status(cot::http::StatusCode::SERVICE_UNAVAILABLE)
+            .header(cot::http::header::CONTENT_TYPE, "text/plain; version=0.0.4")
+            .body(Body::fixed("furumusic_metrics_unavailable 1\n"))
+            .expect("valid response"));
+    }
+    let pg_pool = pool
+        .get_or_init(|| async {
+            sqlx::postgres::PgPoolOptions::new()
+                .max_connections(2)
+                .connect(&config.database_url)
+                .await
+                .expect("metrics pool")
+        })
+        .await;
+    let body = metrics::render(pg_pool, &config).await;
+    Ok(cot::http::Response::builder()
+        .status(cot::http::StatusCode::OK)
+        .header(cot::http::header::CONTENT_TYPE, "text/plain; version=0.0.4")
+        .body(Body::fixed(body))
+        .expect("valid response"))
+}
+
+async fn share_track_handler(
+    session: Session,
+    db: Database,
+    Path(path): Path<SharePathId>,
+) -> cot::Result<cot::response::Response> {
+    let location = if path.id > 0 {
+        format!("/?track={}", path.id)
+    } else {
+        "/".to_string()
+    };
+    if auth::get_session_user(&session, &db).await.is_none() {
+        auth::remember_post_login_redirect(&session, &location).await?;
+        return Ok(auth::redirect("/login"));
+    }
+    Ok(auth::redirect(&location))
+}
+
+async fn share_release_handler(
+    session: Session,
+    db: Database,
+    Path(path): Path<SharePathId>,
+) -> cot::Result<cot::response::Response> {
+    let location = if path.id > 0 {
+        format!("/?release={}", path.id)
+    } else {
+        "/".to_string()
+    };
+    if auth::get_session_user(&session, &db).await.is_none() {
+        auth::remember_post_login_redirect(&session, &location).await?;
+        return Ok(auth::redirect("/login"));
+    }
+    Ok(auth::redirect(&location))
+}
+
+async fn share_playlist_handler(
+    session: Session,
+    db: Database,
+    Path(path): Path<SharePathToken>,
+) -> cot::Result<cot::response::Response> {
+    let token = path.token.trim();
+    let location = if is_share_token(token) {
+        format!("/?playlist_share={token}")
+    } else {
+        "/".to_string()
+    };
+    if auth::get_session_user(&session, &db).await.is_none() {
+        auth::remember_post_login_redirect(&session, &location).await?;
+        return Ok(auth::redirect("/login"));
+    }
+    Ok(auth::redirect(&location))
+}
+
 // ---------------------------------------------------------------------------
 // App
 // ---------------------------------------------------------------------------
 
 struct FuruApp {
     config: Arc<AppConfig>,
+    pool: Arc<tokio::sync::OnceCell<sqlx::PgPool>>,
 }
 
 impl App for FuruApp {
@@ -166,23 +305,52 @@ impl App for FuruApp {
             ),
             Route::with_handler_and_name(
                 "/",
-                |session: Session, db: Database, i18n: I18n| async move {
-                    index(session, db, i18n).await
+                |session: Session, db: Database, i18n: I18n, query: UrlQuery<IndexQuery>| async move {
+                    index(session, db, i18n, query).await
                 },
                 "index",
             ),
+            Route::with_handler_and_name(
+                "/share/track/{id}",
+                get(share_track_handler),
+                "share_track",
+            ),
+            Route::with_handler_and_name(
+                "/share/release/{id}",
+                get(share_release_handler),
+                "share_release",
+            ),
+            Route::with_handler_and_name(
+                "/share/playlist/{token}",
+                get(share_playlist_handler),
+                "share_playlist",
+            ),
+            Route::with_handler_and_name(
+                "/metrics",
+                get({
+                    let config = Arc::clone(&self.config);
+                    let pool = Arc::clone(&self.pool);
+                    move || {
+                        let config = Arc::clone(&config);
+                        let pool = Arc::clone(&pool);
+                        async move { metrics_handler(config, pool).await }
+                    }
+                }),
+                "metrics",
+            ),
             Route::with_handler_and_name(
                 "/login",
                 get({
                     let config = Arc::clone(&self.config);
-                    move |i18n: I18n, db: Database| {
+                    move |i18n: I18n, db: Database, query: UrlQuery<LoginQuery>| {
                         let config = Arc::clone(&config);
                         async move {
                             // No users at all → redirect to first-run setup
                             if User::count_all(&db).await.unwrap_or(0) == 0 {
                                 return Ok(auth::redirect("/admin/setup"));
                             }
-                            login_page_handler(i18n, &config, db, String::new())
+                            let message = query.0.error.unwrap_or_default();
+                            login_page_handler(i18n, &config, db, message)
                                 .await?
                                 .into_response()
                         }
@@ -200,6 +368,11 @@ impl App for FuruApp {
                             let data = match result {
                                 FormResult::Ok(data) => data,
                                 FormResult::ValidationError(_) => {
+                                    metrics::record_auth_attempt(
+                                        "password",
+                                        "failure",
+                                        "validation_error",
+                                    );
                                     let msg = i18n.t.login_invalid.to_owned();
                                     return login_page_handler(i18n, &config, db, msg)
                                         .await?
@@ -207,6 +380,15 @@ impl App for FuruApp {
                                 }
                             };
 
+                            let (live_config, _) = AppConfig::load_with_db(&db).await;
+                            if !live_config.auth_password_enabled {
+                                metrics::record_auth_attempt("password", "failure", "disabled");
+                                let msg = i18n.t.login_disabled.to_owned();
+                                return login_page_handler(i18n, &config, db, msg)
+                                    .await?
+                                    .into_response();
+                            }
+
                             // Try to authenticate
                             if let Ok(Some(user)) = User::get_by_username(&db, &data.username).await
                             {
@@ -215,14 +397,24 @@ impl App for FuruApp {
                                     match hash.verify(&password) {
                                         PasswordVerificationResult::Ok
                                         | PasswordVerificationResult::OkObsolete(_) => {
+                                            let redirect_to =
+                                                auth::get_post_login_redirect(&session)
+                                                    .await?
+                                                    .unwrap_or_else(|| "/".to_string());
                                             auth::login(&session, user.id_val()).await?;
-                                            return Ok(auth::redirect("/"));
+                                            auth::clear_post_login_redirect(&session).await?;
+                                            metrics::record_auth_attempt(
+                                                "password", "success", "ok",
+                                            );
+                                            metrics::record_session_created("password");
+                                            return Ok(auth::redirect(&redirect_to));
                                         }
                                         PasswordVerificationResult::Invalid => {}
                                     }
                                 }
                             }
 
+                            metrics::record_auth_attempt("password", "failure", "bad_credentials");
                             let msg = i18n.t.login_invalid.to_owned();
                             login_page_handler(i18n, &config, db, msg)
                                 .await?
@@ -244,6 +436,16 @@ impl App for FuruApp {
                 get(oidc::oidc_callback_handler),
                 "oidc_callback",
             ),
+            Route::with_handler_and_name(
+                "/auth/mobile/oidc/start",
+                get(oidc::oidc_mobile_start_handler),
+                "mobile_oidc_start",
+            ),
+            Route::with_handler_and_name(
+                "/auth/mobile/oidc/callback",
+                get(oidc::oidc_mobile_callback_handler),
+                "mobile_oidc_callback",
+            ),
         ])
     }
 }
@@ -332,6 +534,7 @@ impl Project for FuruProject {
         context: &cot::project::MiddlewareContext,
     ) -> cot::project::RootHandler {
         handler
+            .middleware(metrics::MetricsLayer)
             .middleware(StaticFilesMiddleware::from_context(context))
             .middleware(SessionMiddleware::from_context(context))
             .build()
@@ -357,10 +560,18 @@ impl Project for FuruProject {
                 .await;
         });
 
+        // Join the federation at boot when it was left enabled (the settings
+        // live in the config KV table; changes apply live from the admin).
+        let fed_config = Arc::clone(&self.app_config);
+        tokio::spawn(async move {
+            federation::handle().boot(&fed_config).await;
+        });
+
         apps.register(cot::session::db::SessionApp::new());
         apps.register_with_views(
             FuruApp {
                 config: Arc::clone(&self.app_config),
+                pool: Arc::new(tokio::sync::OnceCell::new()),
             },
             "",
         );

src/music/mod.rs

@@ -1865,6 +1865,617 @@ pub mod db_migrations {
             &[Operation::custom(create_entity_genre_tags).build()];
     }
 
+    // -- M0036: External metadata identifiers --------------------------------
+
+    #[cot::db::migrations::migration_op]
+    async fn create_external_metadata_ids(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__external_metadata_id (
+                    id BIGSERIAL PRIMARY KEY,
+                    entity_kind VARCHAR(32) NOT NULL,
+                    entity_id BIGINT NOT NULL,
+                    source VARCHAR(32) NOT NULL,
+                    id_kind VARCHAR(64) NOT NULL,
+                    external_id VARCHAR(255) NOT NULL,
+                    confidence DOUBLE PRECISION NOT NULL DEFAULT 1,
+                    updated_at VARCHAR(32) NOT NULL,
+                    UNIQUE(entity_kind, entity_id, source, id_kind)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_external_metadata_id_lookup
+                   ON furumusic__external_metadata_id (source, id_kind, external_id)",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0036CreateExternalMetadataIds;
+
+    impl migrations::Migration for M0036CreateExternalMetadataIds {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0036_create_external_metadata_ids";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0035_create_entity_genre_tags",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_external_metadata_ids).build()];
+    }
+
+    // -- M0037: Shared playlist snapshots ------------------------------------
+
+    #[cot::db::migrations::migration_op]
+    async fn create_playlist_share_links(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__playlist_share_link (
+                    token VARCHAR(64) PRIMARY KEY,
+                    creator_user_id BIGINT NOT NULL,
+                    title TEXT NOT NULL,
+                    track_ids_json TEXT NOT NULL,
+                    created_at VARCHAR(32) NOT NULL
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_playlist_share_link_creator
+                   ON furumusic__playlist_share_link (creator_user_id, created_at DESC)",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0037CreatePlaylistShareLinks;
+
+    impl migrations::Migration for M0037CreatePlaylistShareLinks {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0037_create_playlist_share_links";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0036_create_external_metadata_ids",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_playlist_share_links).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_fed_device_sync(ctx: migrations::MigrationContext<'_>) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__federation_content_id_cache (
+                    media_file_id BIGINT PRIMARY KEY,
+                    sha256_hash TEXT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    updated_at TEXT NOT NULL
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_content_id_cache_content_id
+                   ON furumusic__federation_content_id_cache (content_id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_device_identity (
+                    user_id BIGINT PRIMARY KEY,
+                    device_id TEXT NOT NULL UNIQUE,
+                    group_id TEXT NOT NULL,
+                    device_name TEXT NOT NULL,
+                    local_seq BIGINT NOT NULL DEFAULT 0,
+                    last_hlc_ms BIGINT NOT NULL DEFAULT 0,
+                    local_seeded_at_ms BIGINT NOT NULL DEFAULT 0,
+                    last_sync TEXT,
+                    last_error TEXT
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_device (
+                    user_id BIGINT NOT NULL,
+                    device_id TEXT NOT NULL,
+                    name TEXT NOT NULL DEFAULT '',
+                    client_version TEXT NOT NULL DEFAULT '',
+                    protocol_version INTEGER NOT NULL DEFAULT 1,
+                    endpoint_id TEXT NOT NULL DEFAULT '',
+                    endpoint_ticket TEXT NOT NULL DEFAULT '',
+                    trusted_at_ms BIGINT,
+                    last_seen_ms BIGINT,
+                    revoked_at_ms BIGINT,
+                    revoked_by TEXT,
+                    revoke_cutoff_seq BIGINT,
+                    PRIMARY KEY (user_id, device_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX IF NOT EXISTS idx_fed_device_single_user
+                   ON furumusic__fed_device (device_id)
+                 WHERE trusted_at_ms IS NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_device_invite (
+                    invite_id TEXT PRIMARY KEY,
+                    user_id BIGINT NOT NULL,
+                    secret_hash TEXT NOT NULL,
+                    expires_at_ms BIGINT NOT NULL,
+                    created_at_ms BIGINT NOT NULL,
+                    used_at_ms BIGINT
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_pending_pairing (
+                    request_id TEXT PRIMARY KEY,
+                    user_id BIGINT NOT NULL,
+                    device_id TEXT NOT NULL,
+                    name TEXT NOT NULL,
+                    client_version TEXT NOT NULL,
+                    endpoint_id TEXT NOT NULL,
+                    endpoint_ticket TEXT NOT NULL,
+                    invite_id TEXT NOT NULL,
+                    created_at_ms BIGINT NOT NULL,
+                    answered_at_ms BIGINT,
+                    status TEXT NOT NULL,
+                    requester_group_id TEXT,
+                    requester_group_active_devices BIGINT NOT NULL DEFAULT 1,
+                    requester_group_devices_json TEXT NOT NULL DEFAULT '[]',
+                    use_requester_group BOOLEAN NOT NULL DEFAULT false
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_fed_pending_pairing_user_status
+                   ON furumusic__fed_pending_pairing (user_id, status, created_at_ms DESC)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_sync_ops (
+                    user_id BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    origin_device_id TEXT NOT NULL,
+                    seq BIGINT NOT NULL,
+                    kind TEXT NOT NULL,
+                    payload_json JSONB NOT NULL,
+                    hlc_ms BIGINT NOT NULL,
+                    received_at_ms BIGINT NOT NULL,
+                    tombstone BOOLEAN NOT NULL DEFAULT false,
+                    PRIMARY KEY (user_id, op_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_fed_sync_ops_origin_seq
+                   ON furumusic__fed_sync_ops (user_id, origin_device_id, seq)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_fed_sync_ops_tombstone
+                   ON furumusic__fed_sync_ops (user_id, tombstone)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_sync_vector (
+                    user_id BIGINT NOT NULL,
+                    device_id TEXT NOT NULL,
+                    max_seq BIGINT NOT NULL,
+                    PRIMARY KEY (user_id, device_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_peer_ack (
+                    user_id BIGINT NOT NULL,
+                    peer_device_id TEXT NOT NULL,
+                    origin_device_id TEXT NOT NULL,
+                    max_seq BIGINT NOT NULL,
+                    updated_at_ms BIGINT NOT NULL,
+                    PRIMARY KEY (user_id, peer_device_id, origin_device_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_state_like (
+                    user_id BIGINT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    liked BOOLEAN NOT NULL,
+                    hlc_ms BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    local_track_id BIGINT,
+                    fed_json JSONB,
+                    PRIMARY KEY (user_id, content_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_state_playlist (
+                    user_id BIGINT NOT NULL,
+                    playlist_id TEXT NOT NULL,
+                    local_playlist_id BIGINT,
+                    title TEXT NOT NULL,
+                    deleted BOOLEAN NOT NULL DEFAULT false,
+                    hlc_ms BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    PRIMARY KEY (user_id, playlist_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX IF NOT EXISTS idx_fed_state_playlist_local
+                   ON furumusic__fed_state_playlist (user_id, local_playlist_id)
+                 WHERE local_playlist_id IS NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_state_playlist_item (
+                    user_id BIGINT NOT NULL,
+                    playlist_id TEXT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    present BOOLEAN NOT NULL DEFAULT true,
+                    position BIGINT NOT NULL DEFAULT 0,
+                    hlc_ms BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    local_track_id BIGINT,
+                    fed_json JSONB,
+                    PRIMARY KEY (user_id, playlist_id, content_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_fed_state_playlist_item_playlist
+                   ON furumusic__fed_state_playlist_item
+                      (user_id, playlist_id, present, position)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_playback_applied (
+                    user_id BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    applied_at_ms BIGINT NOT NULL,
+                    PRIMARY KEY (user_id, op_id)
+                )",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0038CreateFedDeviceSync;
+
+    impl migrations::Migration for M0038CreateFedDeviceSync {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0038_create_fed_device_sync";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0037_create_playlist_share_links",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_fed_device_sync).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn ensure_federation_content_id_cache(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__federation_content_id_cache (
+                    media_file_id BIGINT PRIMARY KEY,
+                    sha256_hash TEXT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    updated_at TEXT NOT NULL
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_content_id_cache_content_id
+                   ON furumusic__federation_content_id_cache (content_id)",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0039EnsureFederationContentIdCache;
+
+    impl migrations::Migration for M0039EnsureFederationContentIdCache {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0039_ensure_federation_content_id_cache";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0038_create_fed_device_sync",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(ensure_federation_content_id_cache).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_content_addressed_music_refs(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        // A track reference is durable user-facing identity. `local_track_id`
+        // is availability, not identity: it may become non-NULL after a
+        // federated track is materialized without changing likes/playlists.
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__track_ref (
+                    id BIGSERIAL PRIMARY KEY,
+                    content_id TEXT NOT NULL UNIQUE,
+                    local_track_id BIGINT UNIQUE,
+                    title TEXT NOT NULL,
+                    release_title TEXT,
+                    year INTEGER,
+                    duration_seconds DOUBLE PRECISION,
+                    metadata_json JSONB NOT NULL DEFAULT '{}'::jsonb,
+                    metadata_authority TEXT NOT NULL DEFAULT 'local',
+                    created_at TEXT NOT NULL,
+                    updated_at TEXT NOT NULL
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_track_ref_local_track
+                   ON furumusic__track_ref (local_track_id)
+                 WHERE local_track_id IS NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__federation_track_source (
+                    track_ref_id BIGINT NOT NULL REFERENCES furumusic__track_ref(id)
+                        ON DELETE CASCADE,
+                    owner_peer_id TEXT NOT NULL,
+                    item_id TEXT NOT NULL,
+                    last_seen_ms BIGINT NOT NULL,
+                    metadata_json JSONB NOT NULL DEFAULT '{}'::jsonb,
+                    PRIMARY KEY (owner_peer_id, item_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_federation_track_source_ref
+                   ON furumusic__federation_track_source (track_ref_id, last_seen_ms DESC)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "ALTER TABLE furumusic__user_liked_track
+                   ADD COLUMN IF NOT EXISTS track_ref_id BIGINT
+                       REFERENCES furumusic__track_ref(id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX IF NOT EXISTS idx_user_liked_track_ref_uniq
+                   ON furumusic__user_liked_track (user_id, track_ref_id)
+                 WHERE track_ref_id IS NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "ALTER TABLE furumusic__playlist_track
+                   ADD COLUMN IF NOT EXISTS track_ref_id BIGINT
+                       REFERENCES furumusic__track_ref(id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_playlist_track_ref
+                   ON furumusic__playlist_track (track_ref_id)
+                 WHERE track_ref_id IS NOT NULL",
+            )
+            .await?;
+        // History deliberately remains local-track based. Only the web
+        // player's existing playback report records history and triggers
+        // Last.fm scrobbling.
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0040CreateContentAddressedMusicRefs;
+
+    impl migrations::Migration for M0040CreateContentAddressedMusicRefs {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0040_create_content_addressed_music_refs";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0039_ensure_federation_content_id_cache",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_content_addressed_music_refs).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_synced_listen_history(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__listen_event (
+                    user_id BIGINT NOT NULL,
+                    listen_id TEXT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    local_track_id BIGINT,
+                    origin_device_id TEXT NOT NULL,
+                    started_at_ms BIGINT NOT NULL,
+                    listened_ms BIGINT NOT NULL,
+                    track_duration_ms BIGINT,
+                    ended_reason TEXT NOT NULL,
+                    qualified BOOLEAN NOT NULL,
+                    metadata_json JSONB NOT NULL,
+                    created_at TEXT NOT NULL,
+                    PRIMARY KEY (user_id, listen_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_listen_event_user_time
+                   ON furumusic__listen_event (user_id, started_at_ms DESC, listen_id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_listen_event_content
+                   ON furumusic__listen_event (user_id, content_id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "INSERT INTO furumusic__listen_event
+                    (user_id, listen_id, content_id, local_track_id,
+                     origin_device_id, started_at_ms, listened_ms,
+                     track_duration_ms, ended_reason, qualified,
+                     metadata_json, created_at)
+                 SELECT ph.user_id,
+                        'legacy-web:' || ph.id::text,
+                        tr.content_id,
+                        ph.track_id,
+                        ident.device_id,
+                        (EXTRACT(EPOCH FROM ph.played_at::timestamptz) * 1000)::bigint,
+                        COALESCE(ph.duration_listened, 0)::bigint * 1000,
+                        (t.duration_seconds * 1000)::bigint,
+                        CASE WHEN ph.completed THEN '\"finished\"' ELSE '\"unknown\"' END,
+                        ph.completed,
+                        jsonb_build_object(
+                            'title', t.title::text,
+                            'artist_names', COALESCE((
+                                SELECT jsonb_agg(a.name::text ORDER BY ta.position)
+                                  FROM furumusic__track_artist ta
+                                  JOIN furumusic__artist a ON a.id = ta.artist_id
+                                 WHERE ta.track_id = t.id
+                                   AND ta.role <> 'featuring'
+                            ), '[]'::jsonb),
+                            'featured_artist_names', COALESCE((
+                                SELECT jsonb_agg(a.name::text ORDER BY ta.position)
+                                  FROM furumusic__track_artist ta
+                                  JOIN furumusic__artist a ON a.id = ta.artist_id
+                                 WHERE ta.track_id = t.id
+                                   AND ta.role = 'featuring'
+                            ), '[]'::jsonb),
+                            'release_title', r.title::text
+                        ),
+                        ph.played_at::text
+                   FROM furumusic__play_history ph
+                   JOIN furumusic__track t ON t.id = ph.track_id
+                   JOIN furumusic__track_ref tr ON tr.local_track_id = ph.track_id
+                   JOIN furumusic__fed_device_identity ident
+                     ON ident.user_id = ph.user_id
+                   LEFT JOIN furumusic__release r ON r.id = t.release_id
+                 ON CONFLICT (user_id, listen_id) DO NOTHING",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "ALTER TABLE furumusic__lastfm_scrobble_outbox
+                   ALTER COLUMN track_id DROP NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "ALTER TABLE furumusic__lastfm_scrobble_outbox
+                   ADD COLUMN IF NOT EXISTS track_title TEXT,
+                   ADD COLUMN IF NOT EXISTS artist_name TEXT,
+                   ADD COLUMN IF NOT EXISTS album_title TEXT",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0041CreateSyncedListenHistory;
+
+    impl migrations::Migration for M0041CreateSyncedListenHistory {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0041_create_synced_listen_history";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0040_create_content_addressed_music_refs",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_synced_listen_history).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn repair_legacy_listen_qualification(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "UPDATE furumusic__listen_event le
+                    SET qualified = (
+                        ph.completed
+                        OR (
+                            COALESCE(ph.duration_listened, 0) >= 5
+                            AND COALESCE(t.duration_seconds, 0) > 0
+                            AND COALESCE(ph.duration_listened, 0) >= LEAST(
+                                COALESCE(t.duration_seconds, 0) / 2.0,
+                                240.0
+                            )
+                        )
+                    )
+                   FROM furumusic__play_history ph
+                   JOIN furumusic__track t ON t.id = ph.track_id
+                  WHERE le.user_id = ph.user_id
+                    AND le.listen_id = 'legacy-web:' || ph.id::text",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0042RepairLegacyListenQualification;
+
+    impl migrations::Migration for M0042RepairLegacyListenQualification {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0042_repair_legacy_listen_qualification";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0041_create_synced_listen_history",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(repair_legacy_listen_qualification).build()];
+    }
+
     pub const MIGRATIONS: &[&SyncDynMigration] = &[
         &M0006CreateMediaFile,
         &M0007CreateArtist,
@@ -1891,5 +2502,12 @@ pub mod db_migrations {
         &M0033CreateLastfmScrobbling,
         &M0034CreateArtworkLookupState,
         &M0035CreateEntityGenreTags,
+        &M0036CreateExternalMetadataIds,
+        &M0037CreatePlaylistShareLinks,
+        &M0038CreateFedDeviceSync,
+        &M0039EnsureFederationContentIdCache,
+        &M0040CreateContentAddressedMusicRefs,
+        &M0041CreateSyncedListenHistory,
+        &M0042RepairLegacyListenQualification,
     ];
 }

src/oidc.rs

@@ -4,6 +4,7 @@ use std::sync::LazyLock;
 use std::time::Instant;
 
 use cot::db::Database;
+use cot::request::extractors::UrlQuery;
 use cot::session::Session;
 use openidconnect::core::{CoreClient, CoreProviderMetadata};
 use openidconnect::{
@@ -54,6 +55,13 @@ const SESSION_NONCE: &str = "oidc_nonce";
 const SESSION_PKCE_VERIFIER: &str = "oidc_pkce_verifier";
 const SESSION_REDIRECT_URI: &str = "oidc_redirect_uri";
 
+const SESSION_MOBILE_CSRF_STATE: &str = "mobile_oidc_csrf_state";
+const SESSION_MOBILE_NONCE: &str = "mobile_oidc_nonce";
+const SESSION_MOBILE_PKCE_VERIFIER: &str = "mobile_oidc_pkce_verifier";
+const SESSION_MOBILE_PROVIDER_REDIRECT_URI: &str = "mobile_oidc_provider_redirect_uri";
+const SESSION_MOBILE_APP_REDIRECT_URI: &str = "mobile_oidc_app_redirect_uri";
+const DEFAULT_MOBILE_REDIRECT_URI: &str = "furumi://auth/callback";
+
 // ---------------------------------------------------------------------------
 // Provider cache
 // ---------------------------------------------------------------------------
@@ -172,6 +180,7 @@ pub async fn oidc_start_handler(
         || config.oidc_client_secret.is_empty()
     {
         tracing::warn!("OIDC start requested but SSO is not configured");
+        crate::metrics::record_auth_attempt("oidc", "failure", "not_configured");
         return redirect_login_with_error(i18n.t.login_sso_disabled);
     }
 
@@ -180,6 +189,7 @@ pub async fn oidc_start_handler(
         Ok(c) => c,
         Err(e) => {
             tracing::error!("OIDC provider error: {e}");
+            crate::metrics::record_auth_attempt("oidc", "failure", "provider_error");
             return redirect_login_with_error(i18n.t.login_oidc_error);
         }
     };
@@ -245,13 +255,23 @@ pub struct OidcCallbackQuery {
     state: String,
 }
 
+#[derive(Deserialize)]
+pub struct MobileOidcStartQuery {
+    redirect_uri: Option<String>,
+}
+
+#[derive(Deserialize)]
+pub struct MobileOidcCallbackQuery {
+    code: Option<String>,
+    state: Option<String>,
+    error: Option<String>,
+}
+
 pub async fn oidc_callback_handler(
     i18n: I18n,
     db: Database,
     session: Session,
-    cot::request::extractors::UrlQuery(query): cot::request::extractors::UrlQuery<
-        OidcCallbackQuery,
-    >,
+    UrlQuery(query): UrlQuery<OidcCallbackQuery>,
 ) -> cot::Result<cot::response::Response> {
     let (config, _) = AppConfig::load_with_db(&db).await;
 
@@ -276,19 +296,23 @@ pub async fn oidc_callback_handler(
     // Validate CSRF state.
     let Some(saved_csrf) = saved_csrf else {
         tracing::warn!("OIDC callback: no CSRF state in session");
+        crate::metrics::record_auth_attempt("oidc", "failure", "missing_state");
         return redirect_login_with_error(i18n.t.login_oidc_error);
     };
     if query.state != saved_csrf {
         tracing::warn!("OIDC callback: CSRF state mismatch");
+        crate::metrics::record_auth_attempt("oidc", "failure", "csrf");
         return redirect_login_with_error(i18n.t.login_oidc_error);
     }
 
     let Some(nonce_str) = saved_nonce else {
         tracing::warn!("OIDC callback: no nonce in session");
+        crate::metrics::record_auth_attempt("oidc", "failure", "missing_nonce");
         return redirect_login_with_error(i18n.t.login_oidc_error);
     };
     let Some(pkce_str) = saved_pkce else {
         tracing::warn!("OIDC callback: no PKCE verifier in session");
+        crate::metrics::record_auth_attempt("oidc", "failure", "missing_pkce");
         return redirect_login_with_error(i18n.t.login_oidc_error);
     };
 
@@ -300,6 +324,7 @@ pub async fn oidc_callback_handler(
         Ok(c) => c,
         Err(e) => {
             tracing::error!("OIDC provider error during callback: {e}");
+            crate::metrics::record_auth_attempt("oidc", "failure", "provider_error");
             return redirect_login_with_error(i18n.t.login_oidc_error);
         }
     };
@@ -318,6 +343,7 @@ pub async fn oidc_callback_handler(
         Ok(req) => req,
         Err(e) => {
             tracing::error!("OIDC token endpoint not configured: {e}");
+            crate::metrics::record_auth_attempt("oidc", "failure", "token_config");
             return redirect_login_with_error(i18n.t.login_oidc_error);
         }
     };
@@ -330,6 +356,7 @@ pub async fn oidc_callback_handler(
         Ok(t) => t,
         Err(e) => {
             tracing::error!("OIDC token exchange failed: {e}");
+            crate::metrics::record_auth_attempt("oidc", "failure", "token_exchange");
             return redirect_login_with_error(i18n.t.login_oidc_error);
         }
     };
@@ -340,6 +367,7 @@ pub async fn oidc_callback_handler(
         Some(t) => t,
         None => {
             tracing::error!("OIDC response missing ID token");
+            crate::metrics::record_auth_attempt("oidc", "failure", "missing_id_token");
             return redirect_login_with_error(i18n.t.login_oidc_error);
         }
     };
@@ -348,6 +376,7 @@ pub async fn oidc_callback_handler(
         Ok(c) => c,
         Err(e) => {
             tracing::error!("OIDC ID token verification failed: {e}");
+            crate::metrics::record_auth_attempt("oidc", "failure", "id_token_verify");
             return redirect_login_with_error(i18n.t.login_oidc_error);
         }
     };
@@ -395,6 +424,7 @@ pub async fn oidc_callback_handler(
             config.oidc_user_groups,
             config.oidc_admin_groups,
         );
+        crate::metrics::record_auth_attempt("oidc", "failure", "not_in_group");
         return redirect_login_with_error(i18n.t.login_access_denied);
     }
 
@@ -413,12 +443,20 @@ pub async fn oidc_callback_handler(
         Ok(u) => u,
         Err(e) => {
             tracing::error!("OIDC user provisioning failed: {e}");
+            crate::metrics::record_auth_attempt("oidc", "failure", "provisioning");
             return redirect_login_with_error(i18n.t.login_oidc_error);
         }
     };
 
+    let redirect_to = auth::get_post_login_redirect(&session)
+        .await?
+        .unwrap_or_else(|| "/".to_string());
+
     // Log the user in.
     auth::login(&session, user.id_val()).await?;
+    auth::clear_post_login_redirect(&session).await?;
+    crate::metrics::record_auth_attempt("oidc", "success", "ok");
+    crate::metrics::record_session_created("oidc");
 
     // Clear OIDC session keys.
     let _: Option<String> = session
@@ -438,7 +476,297 @@ pub async fn oidc_callback_handler(
         .await
         .map_err(|e| cot::Error::internal(e.to_string()))?;
 
-    Ok(auth::redirect("/"))
+    Ok(auth::redirect(&redirect_to))
+}
+
+// ---------------------------------------------------------------------------
+// Mobile OIDC flow
+// ---------------------------------------------------------------------------
+
+pub async fn oidc_mobile_start_handler(
+    origin: RequestOrigin,
+    db: Database,
+    session: Session,
+    UrlQuery(query): UrlQuery<MobileOidcStartQuery>,
+) -> cot::Result<cot::response::Response> {
+    let Some(app_redirect_uri) = safe_mobile_redirect_uri(query.redirect_uri.as_deref()) else {
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "bad_redirect_uri");
+        return Ok(text_response(
+            cot::http::StatusCode::BAD_REQUEST,
+            "invalid mobile redirect_uri",
+        ));
+    };
+
+    let (config, _) = AppConfig::load_with_db(&db).await;
+
+    if !config.auth_sso_enabled
+        || config.oidc_issuer.is_empty()
+        || config.oidc_client_id.is_empty()
+        || config.oidc_client_secret.is_empty()
+    {
+        tracing::warn!("Mobile OIDC start requested but SSO is not configured");
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "not_configured");
+        return Ok(mobile_redirect_error(
+            &app_redirect_uri,
+            "sso_not_configured",
+        ));
+    }
+
+    let http = oidc_http_client();
+    let client = match get_or_refresh_provider(&config, &http).await {
+        Ok(c) => c,
+        Err(e) => {
+            tracing::error!("Mobile OIDC provider error: {e}");
+            crate::metrics::record_auth_attempt("mobile_oidc", "failure", "provider_error");
+            return Ok(mobile_redirect_error(&app_redirect_uri, "provider_error"));
+        }
+    };
+
+    let provider_redirect_uri = format!("{}/auth/mobile/oidc/callback", origin.0);
+    let redirect_url = RedirectUrl::new(provider_redirect_uri.clone())
+        .map_err(|e| cot::Error::internal(format!("bad mobile redirect URI: {e}")))?;
+    let client = client.set_redirect_uri(redirect_url);
+
+    let (pkce_challenge, pkce_verifier) = PkceCodeChallenge::new_random_sha256();
+    let (auth_url, csrf_state, nonce) = client
+        .authorize_url(
+            openidconnect::AuthenticationFlow::<openidconnect::core::CoreResponseType>::AuthorizationCode,
+            CsrfToken::new_random,
+            Nonce::new_random,
+        )
+        .add_scope(Scope::new("email".to_string()))
+        .add_scope(Scope::new("profile".to_string()))
+        .set_pkce_challenge(pkce_challenge)
+        .url();
+
+    session
+        .insert(SESSION_MOBILE_CSRF_STATE, csrf_state.secret().clone())
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    session
+        .insert(SESSION_MOBILE_NONCE, nonce.secret().clone())
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    session
+        .insert(SESSION_MOBILE_PKCE_VERIFIER, pkce_verifier.secret().clone())
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    session
+        .insert(
+            SESSION_MOBILE_PROVIDER_REDIRECT_URI,
+            provider_redirect_uri.clone(),
+        )
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    session
+        .insert(SESSION_MOBILE_APP_REDIRECT_URI, app_redirect_uri)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+
+    tracing::info!(
+        auth_url = %auth_url,
+        provider_redirect_uri = %provider_redirect_uri,
+        "Mobile OIDC start: redirecting to provider",
+    );
+
+    Ok(auth::redirect(auth_url.as_str()))
+}
+
+pub async fn oidc_mobile_callback_handler(
+    db: Database,
+    session: Session,
+    UrlQuery(query): UrlQuery<MobileOidcCallbackQuery>,
+) -> cot::Result<cot::response::Response> {
+    let app_redirect_uri = mobile_app_redirect_uri_from_session(&session).await?;
+
+    if query.error.is_some() {
+        tracing::warn!("Mobile OIDC callback returned provider error");
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "provider_denied");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(&app_redirect_uri, "provider_denied"));
+    }
+
+    let Some(code) = query.code else {
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "missing_code");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(&app_redirect_uri, "missing_code"));
+    };
+    let Some(state) = query.state else {
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "missing_state");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(&app_redirect_uri, "missing_state"));
+    };
+
+    let saved_csrf: Option<String> = session
+        .get(SESSION_MOBILE_CSRF_STATE)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    let saved_nonce: Option<String> = session
+        .get(SESSION_MOBILE_NONCE)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    let saved_pkce: Option<String> = session
+        .get(SESSION_MOBILE_PKCE_VERIFIER)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    let provider_redirect_uri: Option<String> = session
+        .get(SESSION_MOBILE_PROVIDER_REDIRECT_URI)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+
+    let Some(saved_csrf) = saved_csrf else {
+        tracing::warn!("Mobile OIDC callback: no CSRF state in session");
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "missing_state");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(&app_redirect_uri, "missing_state"));
+    };
+    if state != saved_csrf {
+        tracing::warn!("Mobile OIDC callback: CSRF state mismatch");
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "csrf");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(&app_redirect_uri, "csrf"));
+    }
+
+    let Some(nonce_str) = saved_nonce else {
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "missing_nonce");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(&app_redirect_uri, "missing_nonce"));
+    };
+    let Some(pkce_str) = saved_pkce else {
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "missing_pkce");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(&app_redirect_uri, "missing_pkce"));
+    };
+    let Some(provider_redirect_uri) = provider_redirect_uri else {
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "missing_redirect_uri");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(
+            &app_redirect_uri,
+            "missing_redirect_uri",
+        ));
+    };
+
+    let (config, _) = AppConfig::load_with_db(&db).await;
+    if !config.auth_sso_enabled
+        || config.oidc_issuer.is_empty()
+        || config.oidc_client_id.is_empty()
+        || config.oidc_client_secret.is_empty()
+    {
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "not_configured");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(
+            &app_redirect_uri,
+            "sso_not_configured",
+        ));
+    }
+
+    let http = oidc_http_client();
+    let client = match get_or_refresh_provider(&config, &http).await {
+        Ok(c) => c,
+        Err(e) => {
+            tracing::error!("Mobile OIDC provider error during callback: {e}");
+            crate::metrics::record_auth_attempt("mobile_oidc", "failure", "provider_error");
+            clear_mobile_oidc_session(&session).await?;
+            return Ok(mobile_redirect_error(&app_redirect_uri, "provider_error"));
+        }
+    };
+    let redirect_url = RedirectUrl::new(provider_redirect_uri)
+        .map_err(|e| cot::Error::internal(format!("bad mobile redirect URI from session: {e}")))?;
+    let client = client.set_redirect_uri(redirect_url);
+
+    let token_request = match client.exchange_code(AuthorizationCode::new(code)) {
+        Ok(req) => req,
+        Err(e) => {
+            tracing::error!("Mobile OIDC token endpoint not configured: {e}");
+            crate::metrics::record_auth_attempt("mobile_oidc", "failure", "token_config");
+            clear_mobile_oidc_session(&session).await?;
+            return Ok(mobile_redirect_error(&app_redirect_uri, "oidc_error"));
+        }
+    };
+    let token_response = token_request
+        .set_pkce_verifier(PkceCodeVerifier::new(pkce_str))
+        .request_async(&http)
+        .await;
+    let token_response = match token_response {
+        Ok(t) => t,
+        Err(e) => {
+            tracing::error!("Mobile OIDC token exchange failed: {e}");
+            crate::metrics::record_auth_attempt("mobile_oidc", "failure", "token_exchange");
+            clear_mobile_oidc_session(&session).await?;
+            return Ok(mobile_redirect_error(&app_redirect_uri, "oidc_error"));
+        }
+    };
+
+    use openidconnect::TokenResponse;
+    let id_token = match token_response.id_token() {
+        Some(t) => t,
+        None => {
+            tracing::error!("Mobile OIDC response missing ID token");
+            crate::metrics::record_auth_attempt("mobile_oidc", "failure", "missing_id_token");
+            clear_mobile_oidc_session(&session).await?;
+            return Ok(mobile_redirect_error(&app_redirect_uri, "oidc_error"));
+        }
+    };
+
+    let nonce = Nonce::new(nonce_str);
+    let claims = match id_token.claims(&client.id_token_verifier(), &nonce) {
+        Ok(c) => c,
+        Err(e) => {
+            tracing::error!("Mobile OIDC ID token verification failed: {e}");
+            crate::metrics::record_auth_attempt("mobile_oidc", "failure", "id_token_verify");
+            clear_mobile_oidc_session(&session).await?;
+            return Ok(mobile_redirect_error(&app_redirect_uri, "oidc_error"));
+        }
+    };
+
+    let sub = claims.subject().to_string();
+    let issuer = claims.issuer().to_string();
+    let email = claims.email().map(|e| e.to_string());
+    let name = claims
+        .name()
+        .and_then(|n| n.get(None))
+        .map(|n| n.to_string());
+    let groups = extract_groups_from_jwt(&id_token.to_string());
+
+    if !is_allowed_by_groups(&groups, &config.oidc_user_groups, &config.oidc_admin_groups) {
+        tracing::warn!(
+            "Mobile OIDC login denied by group allowlist: sub={sub}, groups={groups:?}, user_groups={:?}, admin_groups={:?}",
+            config.oidc_user_groups,
+            config.oidc_admin_groups,
+        );
+        crate::metrics::record_auth_attempt("mobile_oidc", "failure", "not_in_group");
+        clear_mobile_oidc_session(&session).await?;
+        return Ok(mobile_redirect_error(&app_redirect_uri, "access_denied"));
+    }
+
+    let user = match provision_user(
+        &db,
+        &issuer,
+        &sub,
+        email.as_deref(),
+        name.as_deref(),
+        &groups,
+        &config.oidc_admin_groups,
+    )
+    .await
+    {
+        Ok(u) => u,
+        Err(e) => {
+            tracing::error!("Mobile OIDC user provisioning failed: {e}");
+            crate::metrics::record_auth_attempt("mobile_oidc", "failure", "provisioning");
+            clear_mobile_oidc_session(&session).await?;
+            return Ok(mobile_redirect_error(&app_redirect_uri, "oidc_error"));
+        }
+    };
+
+    let exchange_code = auth::create_mobile_exchange_code(&db, user.id_val())
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    clear_mobile_oidc_session(&session).await?;
+
+    crate::metrics::record_auth_attempt("mobile_oidc", "success", "ok");
+    crate::metrics::record_session_created("mobile_oidc");
+    Ok(mobile_redirect_success(&app_redirect_uri, &exchange_code))
 }
 
 // ---------------------------------------------------------------------------
@@ -596,6 +924,307 @@ fn redirect_login_with_error(message: &str) -> cot::Result<cot::response::Respon
     Ok(auth::redirect(&format!("/login?error={encoded}")))
 }
 
+fn text_response(status: cot::http::StatusCode, message: &str) -> cot::response::Response {
+    cot::http::Response::builder()
+        .status(status)
+        .body(cot::Body::fixed(message.to_owned()))
+        .expect("valid response")
+}
+
+async fn mobile_app_redirect_uri_from_session(session: &Session) -> cot::Result<String> {
+    let saved: Option<String> = session
+        .get(SESSION_MOBILE_APP_REDIRECT_URI)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    Ok(safe_mobile_redirect_uri(saved.as_deref())
+        .unwrap_or_else(|| DEFAULT_MOBILE_REDIRECT_URI.to_owned()))
+}
+
+async fn clear_mobile_oidc_session(session: &Session) -> cot::Result<()> {
+    let _: Option<String> = session
+        .remove(SESSION_MOBILE_CSRF_STATE)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    let _: Option<String> = session
+        .remove(SESSION_MOBILE_NONCE)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    let _: Option<String> = session
+        .remove(SESSION_MOBILE_PKCE_VERIFIER)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    let _: Option<String> = session
+        .remove(SESSION_MOBILE_PROVIDER_REDIRECT_URI)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    let _: Option<String> = session
+        .remove(SESSION_MOBILE_APP_REDIRECT_URI)
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    Ok(())
+}
+
+fn safe_mobile_redirect_uri(raw: Option<&str>) -> Option<String> {
+    let value = raw
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .unwrap_or(DEFAULT_MOBILE_REDIRECT_URI);
+    if value.len() > 2048 || value.bytes().any(|b| matches!(b, b'\r' | b'\n')) {
+        return None;
+    }
+
+    let lower = value.to_ascii_lowercase();
+    if lower.starts_with("furumi://") || lower.starts_with("furumusic://") {
+        return Some(value.to_owned());
+    }
+    if is_loopback_http_redirect(&lower) {
+        return Some(value.to_owned());
+    }
+    None
+}
+
+/// RFC 8252 §7.3: native apps without a custom URL scheme (the CLI client)
+/// receive the callback on a loopback listener with an ephemeral port.
+fn is_loopback_http_redirect(lower: &str) -> bool {
+    let Some(rest) = lower.strip_prefix("http://") else {
+        return false;
+    };
+    let host_port = rest.split(['/', '?', '#']).next().unwrap_or("");
+    let Some((host, port)) = host_port.rsplit_once(':') else {
+        return false;
+    };
+    matches!(host, "127.0.0.1" | "localhost" | "[::1]")
+        && !port.is_empty()
+        && port.len() <= 5
+        && port.bytes().all(|b| b.is_ascii_digit())
+}
+
+fn mobile_redirect_success(app_redirect_uri: &str, code: &str) -> cot::response::Response {
+    let deep_link = append_query_param(app_redirect_uri, "code", code);
+    if is_loopback_http_redirect(&app_redirect_uri.to_ascii_lowercase()) {
+        return auth::redirect(&deep_link);
+    }
+    mobile_deep_link_page(
+        "success",
+        "Sign-in complete",
+        "Furumi should open automatically. If it doesn't, use the button or copy the code below.",
+        None,
+        Some(code),
+        &deep_link,
+    )
+}
+
+fn mobile_redirect_error(app_redirect_uri: &str, error: &str) -> cot::response::Response {
+    let deep_link = append_query_param(app_redirect_uri, "error", error);
+    if is_loopback_http_redirect(&app_redirect_uri.to_ascii_lowercase()) {
+        return auth::redirect(&deep_link);
+    }
+    mobile_deep_link_page(
+        "error",
+        "Sign-in failed",
+        "Furumi should open automatically and show the sign-in error.",
+        Some(error),
+        None,
+        &deep_link,
+    )
+}
+
+fn mobile_deep_link_page(
+    state: &str,
+    title: &str,
+    message: &str,
+    detail: Option<&str>,
+    code: Option<&str>,
+    deep_link: &str,
+) -> cot::response::Response {
+    let state_class = html_escape(state);
+    let title_html = html_escape(title);
+    let message_html = html_escape(message);
+    let detail_html = detail
+        .map(|value| format!(r#"<p class="detail">Reason: {}</p>"#, html_escape(value)))
+        .unwrap_or_default();
+    let code_html = code
+        .map(|value| {
+            format!(
+                r#"<p class="hint">Signing in from a terminal? Paste this code there:</p>
+    <input class="code" readonly value="{}" onclick="this.select()">"#,
+                html_escape(value)
+            )
+        })
+        .unwrap_or_default();
+    let deep_link_html = html_escape(deep_link);
+    let deep_link_js =
+        serde_json::to_string(deep_link).expect("serializing URL string cannot fail");
+
+    let html = format!(
+        r#"<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>{title_html}</title>
+  <style>
+    :root {{
+      color-scheme: light dark;
+      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
+      background: #101114;
+      color: #f5f2ea;
+    }}
+    body {{
+      min-height: 100vh;
+      margin: 0;
+      display: grid;
+      place-items: center;
+      padding: 24px;
+      box-sizing: border-box;
+    }}
+    main {{
+      width: min(420px, 100%);
+      text-align: center;
+    }}
+    .mark {{
+      width: 54px;
+      height: 54px;
+      margin: 0 auto 18px;
+      border-radius: 999px;
+      display: grid;
+      place-items: center;
+      font-size: 18px;
+      font-weight: 700;
+      background: #2f7d52;
+      color: white;
+    }}
+    .mark.error {{
+      background: #9d3d42;
+    }}
+    h1 {{
+      margin: 0 0 10px;
+      font-size: 26px;
+      line-height: 1.15;
+      letter-spacing: 0;
+    }}
+    p {{
+      margin: 0;
+      color: #c9c2b7;
+      font-size: 15px;
+      line-height: 1.55;
+    }}
+    .detail {{
+      margin-top: 12px;
+      color: #f1b3b7;
+      overflow-wrap: anywhere;
+    }}
+    a {{
+      display: inline-flex;
+      align-items: center;
+      justify-content: center;
+      min-height: 44px;
+      margin-top: 24px;
+      padding: 0 18px;
+      border-radius: 8px;
+      background: #e8d8a8;
+      color: #17150f;
+      font-weight: 700;
+      text-decoration: none;
+    }}
+    .hint {{
+      margin-top: 14px;
+      font-size: 13px;
+      color: #89847c;
+    }}
+    .code {{
+      width: 100%;
+      margin-top: 8px;
+      padding: 10px 12px;
+      box-sizing: border-box;
+      border: 1px solid #3a3c42;
+      border-radius: 8px;
+      background: #1a1c20;
+      color: #e8d8a8;
+      font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
+      font-size: 13px;
+      text-align: center;
+    }}
+  </style>
+</head>
+<body>
+  <main>
+    <div class="mark {state_class}" aria-hidden="true">{mark}</div>
+    <h1>{title_html}</h1>
+    <p>{message_html}</p>
+    {detail_html}
+    <a href="{deep_link_html}">Open Furumi</a>
+    <p class="hint">If nothing happens, use the button above.</p>
+    {code_html}
+  </main>
+  <script>
+    const deepLink = {deep_link_js};
+    window.setTimeout(() => {{
+      window.location.href = deepLink;
+    }}, 100);
+  </script>
+</body>
+</html>"#,
+        mark = if state == "error" { "!" } else { "OK" }
+    );
+
+    cot::http::Response::builder()
+        .status(cot::http::StatusCode::OK)
+        .header(cot::http::header::CONTENT_TYPE, "text/html; charset=utf-8")
+        .header(cot::http::header::CACHE_CONTROL, "no-store")
+        .body(cot::Body::fixed(html))
+        .expect("valid response")
+}
+
+fn append_query_param(uri: &str, key: &str, value: &str) -> String {
+    let (base, fragment) = uri.split_once('#').unwrap_or((uri, ""));
+    let separator = if base.contains('?') { '&' } else { '?' };
+    let mut out = format!("{base}{separator}{key}={}", urlencoded(value));
+    if !fragment.is_empty() {
+        out.push('#');
+        out.push_str(fragment);
+    }
+    out
+}
+
+fn html_escape(value: &str) -> String {
+    let mut out = String::with_capacity(value.len());
+    for ch in value.chars() {
+        match ch {
+            '&' => out.push_str("&amp;"),
+            '<' => out.push_str("&lt;"),
+            '>' => out.push_str("&gt;"),
+            '"' => out.push_str("&quot;"),
+            '\'' => out.push_str("&#39;"),
+            _ => out.push(ch),
+        }
+    }
+    out
+}
+
+fn extract_groups_from_jwt(token: &str) -> Vec<String> {
+    use base64::Engine;
+
+    let Some(payload_b64) = token.split('.').nth(1) else {
+        return Vec::new();
+    };
+    let Ok(payload_bytes) = base64::engine::general_purpose::URL_SAFE_NO_PAD
+        .decode(payload_b64)
+        .or_else(|_| base64::engine::general_purpose::URL_SAFE.decode(payload_b64))
+    else {
+        return Vec::new();
+    };
+    let Ok(value) = serde_json::from_slice::<serde_json::Value>(&payload_bytes) else {
+        return Vec::new();
+    };
+    let Some(arr) = value.get("groups").and_then(|value| value.as_array()) else {
+        return Vec::new();
+    };
+    arr.iter()
+        .filter_map(|value| value.as_str().map(String::from))
+        .collect()
+}
+
 /// Minimal percent-encoding for query parameter values.
 fn urlencoded(s: &str) -> String {
     let mut out = String::with_capacity(s.len() * 2);
@@ -612,3 +1241,62 @@ fn urlencoded(s: &str) -> String {
     }
     out
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn mobile_oidc_append_query_param_preserves_fragment() {
+        assert_eq!(
+            append_query_param("furumi://auth/callback#done", "code", "a b"),
+            "furumi://auth/callback?code=a%20b#done"
+        );
+        assert_eq!(
+            append_query_param("furumi://auth/callback?desktop=1", "error", "oidc_error"),
+            "furumi://auth/callback?desktop=1&error=oidc_error"
+        );
+    }
+
+    #[test]
+    fn mobile_oidc_html_escape_escapes_page_values() {
+        assert_eq!(
+            html_escape(r#"<tag attr="x&y">'text'</tag>"#),
+            "&lt;tag attr=&quot;x&amp;y&quot;&gt;&#39;text&#39;&lt;/tag&gt;"
+        );
+    }
+
+    #[test]
+    fn mobile_oidc_redirect_uri_allows_only_furumi_schemes() {
+        assert_eq!(
+            safe_mobile_redirect_uri(Some("furumi://auth/callback")).as_deref(),
+            Some("furumi://auth/callback")
+        );
+        assert_eq!(
+            safe_mobile_redirect_uri(Some("furumusic://auth/callback")).as_deref(),
+            Some("furumusic://auth/callback")
+        );
+        assert!(safe_mobile_redirect_uri(Some("https://example.com/callback")).is_none());
+    }
+
+    #[test]
+    fn mobile_oidc_redirect_uri_allows_loopback_http() {
+        assert_eq!(
+            safe_mobile_redirect_uri(Some("http://127.0.0.1:8753/callback")).as_deref(),
+            Some("http://127.0.0.1:8753/callback")
+        );
+        assert_eq!(
+            safe_mobile_redirect_uri(Some("http://localhost:1234/callback")).as_deref(),
+            Some("http://localhost:1234/callback")
+        );
+        assert_eq!(
+            safe_mobile_redirect_uri(Some("http://[::1]:1234/callback")).as_deref(),
+            Some("http://[::1]:1234/callback")
+        );
+        // Non-loopback hosts, missing ports and https stay rejected.
+        assert!(safe_mobile_redirect_uri(Some("http://127.0.0.1/callback")).is_none());
+        assert!(safe_mobile_redirect_uri(Some("http://evil.com:80/callback")).is_none());
+        assert!(safe_mobile_redirect_uri(Some("https://127.0.0.1:80/callback")).is_none());
+        assert!(safe_mobile_redirect_uri(Some("http://127.0.0.1:notaport/x")).is_none());
+    }
+}

src/player/dto.rs

@@ -16,6 +16,7 @@ pub(super) struct Paginated<T: Serialize> {
     pub(super) total: i64,
     pub(super) page: i32,
     pub(super) per_page: i32,
+    pub(super) has_more: bool,
 }
 
 #[derive(Debug, Serialize, JsonSchema)]
@@ -50,6 +51,7 @@ pub(super) struct ArtistRef {
 #[derive(Debug, Clone, Serialize, JsonSchema)]
 pub(super) struct TrackItem {
     pub(super) id: i64,
+    pub(super) content_id: Option<String>,
     pub(super) title: String,
     pub(super) track_number: Option<i32>,
     pub(super) disc_number: Option<i32>,
@@ -73,6 +75,15 @@ pub(super) struct TrackItem {
     pub(super) lastfm_updated_at: Option<String>,
 }
 
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct PlaylistTrackItem {
+    pub(super) playlist_track_id: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) sort_key: Option<i64>,
+    #[serde(flatten)]
+    pub(super) track: TrackItem,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct ArtistAppearanceTrack {
     pub(super) id: i64,
@@ -264,6 +275,24 @@ pub(super) struct PlayerDevicesResponse {
     pub(super) playback_state: Option<PlayerDevicePlaybackStateDto>,
 }
 
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FedDeviceConnectRequest {
+    pub(super) invite: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FedDevicePairingAnswerRequest {
+    pub(super) request_id: String,
+    pub(super) accept: bool,
+    #[serde(default)]
+    pub(super) use_requester_group: bool,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FedDeviceRevokeRequest {
+    pub(super) device_id: String,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct PlayerDevicePollResponse {
     pub(super) device_id: String,
@@ -285,6 +314,19 @@ pub(super) struct PlaylistDetail {
     pub(super) is_public: bool,
     pub(super) is_saved: bool,
     pub(super) kind: String,
+    pub(super) tracks: Vec<PlaylistTrackItem>,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct ShareLinkResponse {
+    pub(super) token: String,
+    pub(super) url: String,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct PlaylistShareDetail {
+    pub(super) token: String,
+    pub(super) title: String,
     pub(super) tracks: Vec<TrackItem>,
 }
 
@@ -311,6 +353,45 @@ pub(super) struct UserProfile {
     pub(super) stats: UserStats,
 }
 
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct OfflineManifestResponse {
+    pub(super) generated_at: String,
+    pub(super) tracks: Vec<OfflineTrackManifestItem>,
+    pub(super) playlists: Vec<OfflinePlaylistManifestItem>,
+    pub(super) liked_track_ids: Vec<i64>,
+    pub(super) followed_artist_ids: Vec<i64>,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct OfflineTrackManifestItem {
+    pub(super) id: i64,
+    pub(super) updated_at: String,
+    pub(super) stream_url: String,
+    pub(super) audio_file_id: i64,
+    pub(super) audio_hash: String,
+    pub(super) audio_size_bytes: i64,
+    pub(super) audio_mime_type: String,
+    pub(super) audio_updated_at: String,
+    pub(super) cover_file_id: Option<i64>,
+    pub(super) cover_url: Option<String>,
+    pub(super) cover_hash: Option<String>,
+    pub(super) cover_updated_at: Option<String>,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct OfflinePlaylistManifestItem {
+    pub(super) id: i64,
+    pub(super) title: String,
+    pub(super) description: Option<String>,
+    pub(super) updated_at: String,
+    pub(super) is_own: bool,
+    pub(super) owner_name: Option<String>,
+    pub(super) is_public: bool,
+    pub(super) is_saved: bool,
+    pub(super) kind: String,
+    pub(super) track_ids: Vec<i64>,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct LastfmStatus {
     pub(super) configured: bool,
@@ -460,14 +541,16 @@ pub(super) struct UserUploadReviewUpdateRequest {
 
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct PlayHistoryItem {
-    pub(super) id: i64,
-    pub(super) track_id: i64,
+    pub(super) id: String,
+    pub(super) track_id: Option<i64>,
     pub(super) track_title: String,
     pub(super) release_title: Option<String>,
-    pub(super) track: TrackItem,
+    pub(super) track: serde_json::Value,
     pub(super) played_at: String,
     pub(super) duration_listened: Option<i32>,
     pub(super) completed: bool,
+    pub(super) device_id: String,
+    pub(super) device_name: String,
 }
 
 #[derive(Debug, Serialize, JsonSchema)]
@@ -483,6 +566,46 @@ pub(super) struct LikeStatus {
     pub(super) liked: bool,
 }
 
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct ContentTrackMutation {
+    pub(super) content_id: String,
+    pub(super) liked: Option<bool>,
+    pub(super) playlist_id: Option<i64>,
+    pub(super) position: Option<i64>,
+    pub(super) federation: Option<serde_json::Value>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct PrepareFederatedTrackRequest {
+    pub(super) content_id: String,
+    pub(super) owner: Option<String>,
+    pub(super) item_id: Option<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationArtworkQuery {
+    pub(super) owner: String,
+    pub(super) item_id: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationArtistQuery {
+    pub(super) name: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationCatalogArtworkQuery {
+    pub(super) owner: String,
+    pub(super) artist: String,
+    pub(super) release: Option<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationArtworkDiscoveryQuery {
+    pub(super) artist: String,
+    pub(super) release: Option<String>,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct LikedIds {
     pub(super) track_ids: Vec<i64>,

src/player/queries.rs

@@ -3,9 +3,11 @@ use serde::Deserialize;
 #[derive(Debug, Deserialize)]
 pub(super) struct HistoryEntry {
     pub(super) track_id: i64,
+    pub(super) listen_id: Option<String>,
     pub(super) started_at: Option<i64>,
     pub(super) duration_listened: Option<i32>,
     pub(super) completed: bool,
+    pub(super) ended_reason: Option<String>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -42,13 +44,26 @@ pub(super) struct AddTracksRequest {
 
 #[derive(Debug, Deserialize)]
 pub(super) struct RemoveTrackRequest {
-    pub(super) track_id: i64,
+    pub(super) track_id: Option<i64>,
+    pub(super) playlist_track_id: Option<i64>,
+}
+
+#[derive(Debug, Deserialize)]
+pub(super) struct ReorderPlaylistRequest {
+    pub(super) playlist_track_ids: Vec<i64>,
+}
+
+#[derive(Debug, Deserialize)]
+pub(super) struct CreatePlaylistShareRequest {
+    pub(super) track_ids: Vec<i64>,
+    pub(super) title: Option<String>,
 }
 
 #[derive(Debug, Deserialize)]
 pub(super) struct PaginationQuery {
     pub(super) page: Option<i32>,
     pub(super) limit: Option<i32>,
+    pub(super) mine: Option<bool>,
 }
 
 #[derive(Debug, Deserialize)]

src/player/rows.rs

@@ -56,6 +56,8 @@ pub(super) struct MediaFileRow {
     pub(super) file_path: String,
     pub(super) mime_type: String,
     pub(super) file_size_bytes: i64,
+    pub(super) sha256_hash: String,
+    pub(super) created_at: String,
 }
 
 #[derive(sqlx::FromRow)]
@@ -93,6 +95,7 @@ pub(super) struct PlaylistInfoRow {
 
 #[derive(sqlx::FromRow)]
 pub(super) struct PlaylistTrackRow {
+    pub(super) playlist_track_id: Option<i64>,
     pub(super) id: i64,
     pub(super) title: String,
     pub(super) track_number: Option<i32>,
@@ -251,34 +254,6 @@ pub(super) struct ReleaseUploaderRow {
     pub(super) track_count: i64,
 }
 
-#[derive(sqlx::FromRow)]
-pub(super) struct PlayHistoryTrackRow {
-    pub(super) history_id: i64,
-    pub(super) played_at: String,
-    pub(super) duration_listened: Option<i32>,
-    pub(super) completed: bool,
-    pub(super) id: i64,
-    pub(super) title: String,
-    pub(super) track_number: Option<i32>,
-    pub(super) disc_number: Option<i32>,
-    pub(super) duration_seconds: f64,
-    pub(super) cover_file_id: Option<i64>,
-    pub(super) release_cover_file_id: Option<i64>,
-    pub(super) release_id: i64,
-    pub(super) release_title: String,
-    pub(super) release_year: Option<i32>,
-    pub(super) uploader_name: String,
-    pub(super) audio_format: Option<String>,
-    pub(super) audio_bitrate: Option<i32>,
-    pub(super) audio_sample_rate: Option<i32>,
-    pub(super) audio_bit_depth: Option<i32>,
-    pub(super) file_size_bytes: Option<i64>,
-    pub(super) lastfm_listeners: Option<i64>,
-    pub(super) lastfm_playcount: Option<i64>,
-    pub(super) lastfm_rating: Option<f64>,
-    pub(super) lastfm_updated_at: Option<String>,
-}
-
 #[derive(sqlx::FromRow)]
 pub(super) struct ReleaseInfoRow {
     pub(super) id: i64,
@@ -287,3 +262,30 @@ pub(super) struct ReleaseInfoRow {
     pub(super) year: Option<i32>,
     pub(super) cover_file_id: Option<i64>,
 }
+
+#[derive(sqlx::FromRow)]
+pub(super) struct OfflineTrackManifestRow {
+    pub(super) id: i64,
+    pub(super) updated_at: String,
+    pub(super) audio_file_id: i64,
+    pub(super) audio_hash: String,
+    pub(super) audio_size_bytes: i64,
+    pub(super) audio_mime_type: String,
+    pub(super) audio_updated_at: String,
+    pub(super) cover_file_id: Option<i64>,
+    pub(super) cover_hash: Option<String>,
+    pub(super) cover_updated_at: Option<String>,
+}
+
+#[derive(sqlx::FromRow)]
+pub(super) struct OfflinePlaylistManifestRow {
+    pub(super) id: i64,
+    pub(super) title: String,
+    pub(super) description: Option<String>,
+    pub(super) updated_at: String,
+    pub(super) is_own: bool,
+    pub(super) owner_name: String,
+    pub(super) is_public: bool,
+    pub(super) is_saved: bool,
+    pub(super) track_ids: Vec<i64>,
+}

src/scheduler/mod.rs

@@ -200,6 +200,12 @@ impl JobRun {
         duration_ms: i64,
         log: &str,
     ) -> cot::db::Result<()> {
+        crate::metrics::record_scheduler_job(
+            self.job_name.as_str(),
+            self.trigger.as_str(),
+            "completed",
+            duration_ms,
+        );
         self.status = LimitedString::new("completed").unwrap();
         self.finished_at = Some(now_iso().to_string());
         self.duration_ms = Some(duration_ms);
@@ -214,6 +220,12 @@ impl JobRun {
         log: &str,
         error: &str,
     ) -> cot::db::Result<()> {
+        crate::metrics::record_scheduler_job(
+            self.job_name.as_str(),
+            self.trigger.as_str(),
+            "failed",
+            duration_ms,
+        );
         self.status = LimitedString::new("failed").unwrap();
         self.finished_at = Some(now_iso().to_string());
         self.duration_ms = Some(duration_ms);
@@ -484,14 +496,24 @@ impl PendingReview {
             .await
     }
 
-    pub async fn exists_for_path(db: &Database, path: &str) -> cot::db::Result<bool> {
-        let all = Self::objects().all(db).await?;
-        let exists = all.iter().any(|r| {
-            let s = r.status.as_str();
-            // "rejected" and "failed" reviews should not block re-discovery
-            s != "rejected" && s != "failed" && r.input_path.as_deref() == Some(path)
-        });
-        Ok(exists)
+    /// Latest review row for an inbox path: `(id, status, updated_at)`.
+    ///
+    /// Used by inbox_discover to decide whether a file needs a new review,
+    /// a requeue of its existing row, or nothing at all — without creating
+    /// a fresh row per retry.
+    pub async fn latest_for_path(
+        pool: &sqlx::PgPool,
+        path: &str,
+    ) -> anyhow::Result<Option<(i64, String, String)>> {
+        let row: Option<(i64, String, String)> = sqlx::query_as(
+            "SELECT id, status::text, updated_at::text \
+             FROM furumusic__pending_review WHERE input_path = $1 \
+             ORDER BY id DESC LIMIT 1",
+        )
+        .bind(path)
+        .fetch_optional(pool)
+        .await?;
+        Ok(row)
     }
 
     /// Mark all "processing" reviews as "failed" — called at scheduler
@@ -1360,6 +1382,7 @@ async fn run_scheduled_job(
     if !live_config.agent_enabled
         && job_name != "lastfm_popularity"
         && job_name != "lastfm_scrobble"
+        && job_name != "archive_cleanup"
         && job_name != "artwork_backfill"
     {
         tracing::warn!(job = job_name, "Skipping: agent_enabled=false");

src/torrents.rs

@@ -777,7 +777,7 @@ impl TorrentService {
 
         self.ensure_memory_job(pool, uploader_user_id, id).await?;
 
-        let (torrent_bytes, output_dir) = {
+        let (torrent_bytes, output_dir, selected_size) = {
             let mut jobs = self.jobs.lock().await;
             let job = jobs.get_mut(id).context("torrent job not found")?;
             if job.user_id != uploader_user_id {
@@ -800,7 +800,11 @@ impl TorrentService {
             job.error = None;
             job.completed_at = None;
             job.updated_at = now_string();
-            (job.torrent_bytes.clone(), job.output_dir.clone())
+            (
+                job.torrent_bytes.clone(),
+                job.output_dir.clone(),
+                job.selected_size(),
+            )
         };
 
         tokio::fs::create_dir_all(&output_dir).await?;
@@ -846,6 +850,7 @@ impl TorrentService {
         let service = Arc::clone(self);
         let pool = pool.clone();
         let id = id.to_string();
+        let download_start = std::time::Instant::now();
         tokio::spawn(async move {
             if let Err(err) = handle.wait_until_completed().await {
                 if service.is_paused(&id).await {
@@ -853,6 +858,11 @@ impl TorrentService {
                 }
                 service.stop_torrent(&handle).await;
                 service.fail_job(&pool, &id, err.to_string()).await;
+                crate::metrics::record_torrent_download(
+                    "failed",
+                    selected_size,
+                    download_start.elapsed(),
+                );
                 return;
             }
             service.stop_torrent(&handle).await;
@@ -861,6 +871,17 @@ impl TorrentService {
                 .await
             {
                 service.fail_job(&pool, &id, err.to_string()).await;
+                crate::metrics::record_torrent_download(
+                    "failed",
+                    selected_size,
+                    download_start.elapsed(),
+                );
+            } else {
+                crate::metrics::record_torrent_download(
+                    "completed",
+                    selected_size,
+                    download_start.elapsed(),
+                );
             }
         });
 

templates/player/modals.html

@@ -122,11 +122,11 @@
                 <div class="torrent-tabs">
                     <button class="torrent-tab-btn"
                             :class="{ active: $store.torrents.activeTab === 'import' }"
-                            @click="$store.torrents.showImportTab()">Import</button>
+                            @click="$store.torrents.showImportTab()">{{ t.player_import }}</button>
                     <button class="torrent-tab-btn"
                             :class="{ active: $store.torrents.activeTab === 'uploads' }"
                             @click="$store.torrents.showUploadsTab()">
-                        <span>My uploads</span>
+                        <span>{{ t.player_my_uploads }}</span>
                         <span class="torrent-tab-count"
                               x-show="$store.torrents.uploadPendingTotal + $store.torrents.uploadQueuedTotal > 0"
                               x-text="$store.torrents.uploadPendingTotal + $store.torrents.uploadQueuedTotal"></span>
@@ -347,7 +347,7 @@
                     <section class="upload-manager-panel">
                         <div class="upload-manager-head">
                             <div>
-                                <h4>My uploaded tracks</h4>
+                                <h4>{{ t.player_my_uploaded_tracks }}</h4>
                                 <p x-text="$store.torrents.uploadSummary()"></p>
                             </div>
                             <button class="modal-btn modal-btn-ghost"
@@ -357,22 +357,22 @@
 
                         <template x-if="$store.torrents.uploadLoaded && $store.torrents.uploadTracks.length === 0 && $store.torrents.uploadPending.length === 0 && $store.torrents.uploadQueued.length === 0">
                             <div class="empty-state torrent-workspace-empty">
-                                <p>No uploaded tracks yet</p>
+                                <p>{{ t.player_no_uploaded_tracks }}</p>
                             </div>
                         </template>
 
                         <div class="upload-manager-grid">
                             <aside class="upload-review-column">
                                 <div class="upload-panel-card">
-                                    <div class="upload-panel-title">Needs approval</div>
-                                    <p class="upload-panel-subtitle" x-text="$store.torrents.uploadPendingTotal + ' pending or failed'"></p>
+                                    <div class="upload-panel-title">{{ t.player_needs_approval }}</div>
+                                    <p class="upload-panel-subtitle" x-text="$store.torrents.uploadPendingTotal + ' {{ t.player_pending_or_failed }}'"></p>
                                     <template x-if="$store.torrents.uploadPending.length === 0">
-                                        <div class="upload-mini-empty">No tracks need approval</div>
+                                        <div class="upload-mini-empty">{{ t.player_no_tracks_need_approval }}</div>
                                     </template>
                                     <div class="upload-review-list">
                                         <template x-for="item in $store.torrents.uploadPending" :key="item.id">
                                             <button class="upload-review-row" :class="{ active: $store.torrents.uploadReviewEditId === item.id, failed: item.status === 'failed' }" @click="$store.torrents.editUploadReview(item)">
-                                                <span class="torrent-status-badge" :class="'status-' + item.status" x-text="item.status"></span>
+                                                <span class="torrent-status-badge" :class="'status-' + item.status" x-text="$store.torrents.uploadStatusLabel(item.status)"></span>
                                                 <span class="upload-review-name" x-text="item.filename"></span>
                                                 <span class="upload-review-error" x-show="item.error_message" x-text="item.error_message"></span>
                                             </button>
@@ -381,67 +381,94 @@
                                 </div>
                                 <template x-if="$store.torrents.uploadQueuedTotal > 0">
                                     <div class="upload-panel-card upload-queue-panel">
-                                        <div class="upload-panel-title">Queued / processing</div>
+                                        <div class="upload-panel-title upload-panel-title-row">
+                                            <span>{{ t.player_queued_processing }}</span>
+                                            <div class="upload-queue-nav" x-show="$store.torrents.uploadQueued.length > $store.torrents.uploadQueuePageSize">
+                                                <span class="upload-queue-range" x-text="$store.torrents.uploadQueueRangeText()"></span>
+                                                <button type="button"
+                                                        class="upload-queue-nav-btn"
+                                                        @click="$store.torrents.uploadQueuePrev()"
+                                                        :disabled="!$store.torrents.uploadQueueCanPrev()"
+                                                        title="{{ t.player_previous }}">
+                                                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.4"><polyline points="15 18 9 12 15 6"/></svg>
+                                                </button>
+                                                <button type="button"
+                                                        class="upload-queue-nav-btn"
+                                                        @click="$store.torrents.uploadQueueNext()"
+                                                        :disabled="!$store.torrents.uploadQueueCanNext()"
+                                                        title="{{ t.player_next }}">
+                                                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.4"><polyline points="9 18 15 12 9 6"/></svg>
+                                                </button>
+                                            </div>
+                                        </div>
                                         <template x-for="item in $store.torrents.compactQueuedUploads()" :key="item.id">
-                                            <div class="upload-queue-row">
-                                                <span class="torrent-status-badge" :class="'status-' + item.status" x-text="item.status"></span>
+                                            <div class="upload-queue-row" :title="$store.torrents.uploadQueueTooltip(item)">
+                                                <span class="torrent-status-badge" :class="'status-' + item.status" x-text="$store.torrents.uploadStatusLabel(item.status)"></span>
                                                 <span class="upload-queue-name" x-text="item.filename"></span>
                                             </div>
                                         </template>
-                                        <div class="upload-mini-empty" x-show="$store.torrents.uploadQueuedTotal > $store.torrents.uploadQueued.length" x-text="'Showing ' + $store.torrents.uploadQueued.length + ' of ' + $store.torrents.uploadQueuedTotal"></div>
+                                        <div class="upload-mini-empty" x-show="$store.torrents.uploadQueuedTotal > $store.torrents.uploadQueued.length" x-text="$store.torrents.uploadQueueOverflowText()"></div>
                                     </div>
                                 </template>
                             </aside>
                             <section class="upload-library-column">
                                 <div class="upload-bulk-bar" x-show="$store.torrents.uploadSelectedCount() > 0">
-                                    <div class="upload-bulk-title" x-text="$store.torrents.uploadSelectedCount() + ' selected'"></div>
-                                    <input type="text" placeholder="Artists" x-model="$store.torrents.uploadBulkDraft.artists">
-                                    <input type="text" placeholder="Featured" x-model="$store.torrents.uploadBulkDraft.featured_artists">
-                                    <input type="text" placeholder="Album" x-model="$store.torrents.uploadBulkDraft.release_title">
-                                    <input type="number" placeholder="Year" x-model="$store.torrents.uploadBulkDraft.release_year">
+                                    <div class="upload-bulk-title" x-text="$store.torrents.uploadSelectedCount() + ' {{ t.player_selected }}'"></div>
+                                    <input type="text" placeholder="{{ t.player_artists }}" x-model="$store.torrents.uploadBulkDraft.artists">
+                                    <input type="text" placeholder="{{ t.player_featured }}" x-model="$store.torrents.uploadBulkDraft.featured_artists">
+                                    <input type="text" placeholder="{{ t.player_album }}" x-model="$store.torrents.uploadBulkDraft.release_title">
+                                    <input type="number" placeholder="{{ t.player_year }}" x-model="$store.torrents.uploadBulkDraft.release_year">
                                     <select x-model="$store.torrents.uploadBulkDraft.release_type">
-                                        <option value="">Type unchanged</option><option value="album">Album</option><option value="single">Single</option><option value="ep">EP</option><option value="compilation">Compilation</option><option value="mixtape">Mixtape</option><option value="live">Live</option><option value="soundtrack">Soundtrack</option><option value="remix">Remix</option><option value="demo">Demo</option>
+                                        <option value="">{{ t.player_type_unchanged }}</option><option value="album">{{ t.player_release_type_album }}</option><option value="single">{{ t.player_release_type_single }}</option><option value="ep">{{ t.player_release_type_ep }}</option><option value="compilation">{{ t.player_release_type_compilation }}</option><option value="mixtape">{{ t.player_release_type_mixtape }}</option><option value="live">{{ t.player_release_type_live }}</option><option value="soundtrack">{{ t.player_release_type_soundtrack }}</option><option value="remix">{{ t.player_release_type_remix }}</option><option value="demo">{{ t.player_release_type_demo }}</option>
                                     </select>
                                     <select x-model="$store.torrents.uploadBulkDraft.hidden">
-                                        <option value="">Visibility unchanged</option><option value="false">Visible</option><option value="true">Hidden</option>
+                                        <option value="">{{ t.player_visibility_unchanged }}</option><option value="false">{{ t.player_visible }}</option><option value="true">{{ t.player_hidden }}</option>
                                     </select>
-                                    <button class="modal-btn modal-btn-primary" @click="$store.torrents.saveUploadBulkEdit()" :disabled="$store.torrents.uploadBulkSaving">Apply</button>
-                                    <button class="modal-btn modal-btn-ghost" @click="$store.torrents.clearUploadSelection()">Clear</button>
+                                    <button class="modal-btn modal-btn-primary" @click="$store.torrents.saveUploadBulkEdit()" :disabled="$store.torrents.uploadBulkSaving">{{ t.player_apply }}</button>
+                                    <button class="modal-btn modal-btn-ghost" @click="$store.torrents.clearUploadSelection()">{{ t.player_clear }}</button>
                                 </div>
                                 <div class="upload-release-tree">
-                                    <template x-for="release in $store.torrents.uploadReleases" :key="release.id">
-                                        <div class="upload-release-node" :class="{ hidden: release.is_hidden }">
-                                            <div class="upload-release-row">
-                                                <button class="torrent-tree-check" :class="$store.torrents.uploadReleaseSelectionState(release)" @click="$store.torrents.toggleUploadReleaseSelection(release)">
-                                                    <template x-if="$store.torrents.uploadReleaseSelectionState(release) === 'checked'"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="3"><polyline points="20 6 9 17 4 12"/></svg></template>
-                                                    <template x-if="$store.torrents.uploadReleaseSelectionState(release) === 'partial'"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="3"><line x1="5" y1="12" x2="19" y2="12"/></svg></template>
-                                                </button>
-                                                <button class="torrent-tree-toggle" :class="{ expanded: $store.torrents.uploadReleaseExpanded(release.id) }" @click="$store.torrents.toggleUploadRelease(release.id)"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="9 18 15 12 9 6"/></svg></button>
-                                                <div class="upload-release-main">
-                                                    <div class="upload-release-title"><span x-text="release.title"></span><span class="upload-hidden-pill" x-show="release.is_hidden">hidden</span></div>
-                                                    <div class="upload-track-meta"><span x-text="$store.torrents.uploadReleaseArtistsText(release)"></span><span>-</span><span x-text="release.year || 'no year'"></span><span>-</span><span x-text="release.tracks.length + ' tracks'"></span></div>
-                                                </div>
-                                                <button class="modal-btn modal-btn-ghost" @click="$store.torrents.editUploadRelease(release)">Edit release</button>
+                                    <template x-for="group in $store.torrents.uploadArtistGroups()" :key="group.key">
+                                        <section class="upload-artist-group">
+                                            <div class="upload-artist-row">
+                                                <div class="upload-artist-name" x-text="group.name"></div>
+                                                <div class="upload-artist-meta" x-text="group.releases.length + ' {{ t.player_releases_count }} - ' + group.trackCount + ' {{ t.player_tracks_count }}'"></div>
                                             </div>
-                                            <div class="upload-track-children" x-show="$store.torrents.uploadReleaseExpanded(release.id)">
-                                                <template x-for="item in release.tracks" :key="item.track.id">
-                                                    <div class="upload-tree-track" :class="{ hidden: item.is_hidden, selected: $store.torrents.selectedUploadTracks.has(item.track.id) }">
-                                                        <button class="torrent-tree-check" :class="{ checked: $store.torrents.selectedUploadTracks.has(item.track.id) }" @click="$store.torrents.toggleUploadTrackSelection(item.track.id)">
-                                                            <template x-if="$store.torrents.selectedUploadTracks.has(item.track.id)"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="3"><polyline points="20 6 9 17 4 12"/></svg></template>
+                                            <template x-for="release in group.releases" :key="release.id">
+                                                <div class="upload-release-node" :class="{ hidden: release.is_hidden }">
+                                                    <div class="upload-release-row">
+                                                        <button class="torrent-tree-check" :class="$store.torrents.uploadReleaseSelectionState(release)" @click="$store.torrents.toggleUploadReleaseSelection(release)">
+                                                            <template x-if="$store.torrents.uploadReleaseSelectionState(release) === 'checked'"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="3"><polyline points="20 6 9 17 4 12"/></svg></template>
+                                                            <template x-if="$store.torrents.uploadReleaseSelectionState(release) === 'partial'"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="3"><line x1="5" y1="12" x2="19" y2="12"/></svg></template>
                                                         </button>
-                                                        <div class="upload-track-main">
-                                                            <div class="upload-track-title"><span x-text="item.track.track_number ? item.track.track_number + '. ' + item.track.title : item.track.title"></span><span class="upload-hidden-pill" x-show="item.is_hidden">hidden</span></div>
-                                                            <div class="upload-track-meta"><span x-text="$store.torrents.uploadArtistsText(item)"></span><span x-show="$store.torrents.uploadFeaturedArtistsText(item)">feat.</span><span x-show="$store.torrents.uploadFeaturedArtistsText(item)" x-text="$store.torrents.uploadFeaturedArtistsText(item)"></span></div>
-                                                        </div>
-                                                        <div class="upload-track-actions">
-                                                            <button class="track-action-btn queue-insert-btn queue-next-btn" @click="$store.queue.addNextInQueue([item.track])" title="{{ t.player_play_next }}"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M5 6h10M5 12h7M5 18h10"/><path d="M17 9l4 3-4 3" fill="currentColor" stroke="none"/></svg></button>
-                                                            <button class="track-action-btn queue-insert-btn queue-end-btn" @click="$store.queue.addToEnd([item.track])" title="{{ t.player_add_to_queue }}"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M5 6h14M5 12h14M5 18h7"/><path d="M17 15l4 3-4 3" fill="currentColor" stroke="none"/></svg></button>
-                                                            <button class="modal-btn modal-btn-ghost" @click="$store.torrents.editUpload(item)">Edit</button>
+                                                        <button class="torrent-tree-toggle" :class="{ expanded: $store.torrents.uploadReleaseExpanded(release.id) }" @click="$store.torrents.toggleUploadRelease(release.id)"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="9 18 15 12 9 6"/></svg></button>
+                                                        <div class="upload-release-main">
+                                                            <div class="upload-release-title"><span x-text="release.title"></span><span class="upload-hidden-pill" x-show="release.is_hidden">{{ t.player_hidden }}</span></div>
+                                                            <div class="upload-track-meta"><span x-text="$store.torrents.uploadReleaseArtistsText(release)"></span><span>-</span><span x-text="release.year || T.noYear"></span><span>-</span><span x-text="release.tracks.length + ' {{ t.player_tracks_count }}'"></span></div>
                                                         </div>
+                                                        <button class="modal-btn modal-btn-ghost" @click="$store.torrents.editUploadRelease(release)">{{ t.player_edit_release }}</button>
                                                     </div>
-                                                </template>
-                                            </div>
-                                        </div>
+                                                    <div class="upload-track-children" x-show="$store.torrents.uploadReleaseExpanded(release.id)">
+                                                        <template x-for="item in release.tracks" :key="item.track.id">
+                                                            <div class="upload-tree-track" :class="{ hidden: item.is_hidden, selected: $store.torrents.selectedUploadTracks.has(item.track.id) }">
+                                                                <button class="torrent-tree-check" :class="{ checked: $store.torrents.selectedUploadTracks.has(item.track.id) }" @click="$store.torrents.toggleUploadTrackSelection(item.track.id)">
+                                                                    <template x-if="$store.torrents.selectedUploadTracks.has(item.track.id)"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="3"><polyline points="20 6 9 17 4 12"/></svg></template>
+                                                                </button>
+                                                                <div class="upload-track-main">
+                                                                    <div class="upload-track-title"><span x-text="item.track.track_number ? item.track.track_number + '. ' + item.track.title : item.track.title"></span><span class="upload-hidden-pill" x-show="item.is_hidden">{{ t.player_hidden }}</span></div>
+                                                                    <div class="upload-track-meta"><span x-text="$store.torrents.uploadArtistsText(item)"></span><span x-show="$store.torrents.uploadFeaturedArtistsText(item)" x-text="T.featuredShort"></span><span x-show="$store.torrents.uploadFeaturedArtistsText(item)" x-text="$store.torrents.uploadFeaturedArtistsText(item)"></span></div>
+                                                                </div>
+                                                                <div class="upload-track-actions">
+                                                                    <button class="track-action-btn queue-insert-btn queue-next-btn" @click="$store.queue.addNextInQueue([item.track])" title="{{ t.player_play_next }}"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M5 6h10M5 12h7M5 18h10"/><path d="M17 9l4 3-4 3" fill="currentColor" stroke="none"/></svg></button>
+                                                                    <button class="track-action-btn queue-insert-btn queue-end-btn" @click="$store.queue.addToEnd([item.track])" title="{{ t.player_add_to_queue }}"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M5 6h14M5 12h14M5 18h7"/><path d="M17 15l4 3-4 3" fill="currentColor" stroke="none"/></svg></button>
+                                                                    <button class="modal-btn modal-btn-ghost" @click="$store.torrents.editUpload(item)">{{ t.player_edit }}</button>
+                                                                </div>
+                                                            </div>
+                                                        </template>
+                                                    </div>
+                                                </div>
+                                            </template>
+                                        </section>
                                     </template>
                                 </div>
                             </section>
@@ -455,7 +482,7 @@
                                             <div class="upload-panel-title" x-text="$store.torrents.uploadEditorKicker()"></div>
                                             <h4 x-text="$store.torrents.uploadEditorTitle()"></h4>
                                         </div>
-                                        <button class="track-action-btn" @click="$store.torrents.closeUploadEditor()" title="Close">
+                                        <button class="track-action-btn" @click="$store.torrents.closeUploadEditor()" title="{{ t.player_close }}">
                                             <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.4">
                                                 <path d="M18 6L6 18M6 6l12 12"/>
                                             </svg>
@@ -464,53 +491,53 @@
 
                                     <template x-if="$store.torrents.uploadReviewDraft">
                                         <div class="upload-editor-form">
-                                            <label class="upload-field upload-field-half"><span>Title</span><input type="text" x-model="$store.torrents.uploadReviewDraft.title"></label>
-                                            <label class="upload-field upload-field-half"><span>Artist</span><input type="text" x-model="$store.torrents.uploadReviewDraft.artist"></label>
-                                            <label class="upload-field upload-field-half"><span>Album</span><input type="text" x-model="$store.torrents.uploadReviewDraft.album"></label>
-                                            <label class="upload-field upload-field-half"><span>Featured</span><input type="text" x-model="$store.torrents.uploadReviewDraft.featured_artists" placeholder="Artist, Artist"></label>
-                                            <label class="upload-field upload-field-compact"><span>Year</span><input type="number" x-model="$store.torrents.uploadReviewDraft.year"></label>
-                                            <label class="upload-field upload-field-compact"><span>Track #</span><input type="number" min="1" x-model="$store.torrents.uploadReviewDraft.track_number"></label>
-                                            <label class="upload-field upload-field-compact"><span>Genre</span><input type="text" x-model="$store.torrents.uploadReviewDraft.genre"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_title }}</span><input type="text" x-model="$store.torrents.uploadReviewDraft.title"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_artist }}</span><input type="text" x-model="$store.torrents.uploadReviewDraft.artist"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_album }}</span><input type="text" x-model="$store.torrents.uploadReviewDraft.album"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_featured }}</span><input type="text" x-model="$store.torrents.uploadReviewDraft.featured_artists" placeholder="{{ t.player_artists_placeholder }}"></label>
+                                            <label class="upload-field upload-field-compact"><span>{{ t.player_year }}</span><input type="number" x-model="$store.torrents.uploadReviewDraft.year"></label>
+                                            <label class="upload-field upload-field-compact"><span>{{ t.player_track_number }}</span><input type="number" min="1" x-model="$store.torrents.uploadReviewDraft.track_number"></label>
+                                            <label class="upload-field upload-field-compact"><span>{{ t.player_genre }}</span><input type="text" x-model="$store.torrents.uploadReviewDraft.genre"></label>
                                             <label class="upload-field upload-field-compact">
-                                                <span>Type</span>
+                                                <span>{{ t.player_type }}</span>
                                                 <select x-model="$store.torrents.uploadReviewDraft.release_type">
-                                                    <option value="album">Album</option><option value="single">Single</option><option value="ep">EP</option><option value="compilation">Compilation</option><option value="mixtape">Mixtape</option><option value="live">Live</option><option value="soundtrack">Soundtrack</option><option value="remix">Remix</option><option value="demo">Demo</option>
+                                                    <option value="album">{{ t.player_release_type_album }}</option><option value="single">{{ t.player_release_type_single }}</option><option value="ep">{{ t.player_release_type_ep }}</option><option value="compilation">{{ t.player_release_type_compilation }}</option><option value="mixtape">{{ t.player_release_type_mixtape }}</option><option value="live">{{ t.player_release_type_live }}</option><option value="soundtrack">{{ t.player_release_type_soundtrack }}</option><option value="remix">{{ t.player_release_type_remix }}</option><option value="demo">{{ t.player_release_type_demo }}</option>
                                                 </select>
                                             </label>
-                                            <label class="upload-field upload-field-wide"><span>Notes</span><textarea rows="4" x-model="$store.torrents.uploadReviewDraft.notes"></textarea></label>
+                                            <label class="upload-field upload-field-wide"><span>{{ t.player_notes }}</span><textarea rows="4" x-model="$store.torrents.uploadReviewDraft.notes"></textarea></label>
                                             <div class="upload-editor-actions">
-                                                <button class="modal-btn modal-btn-danger" @click="$store.torrents.deleteUploadReview()" :disabled="$store.torrents.uploadReviewSavingId === $store.torrents.uploadReviewEditId">Delete review</button>
-                                                <button class="modal-btn modal-btn-primary" @click="$store.torrents.approveUploadReview()" :disabled="$store.torrents.uploadReviewSavingId === $store.torrents.uploadReviewEditId">Approve</button>
+                                                <button class="modal-btn modal-btn-danger" @click="$store.torrents.deleteUploadReview()" :disabled="$store.torrents.uploadReviewSavingId === $store.torrents.uploadReviewEditId">{{ t.player_delete_review }}</button>
+                                                <button class="modal-btn modal-btn-primary" @click="$store.torrents.approveUploadReview()" :disabled="$store.torrents.uploadReviewSavingId === $store.torrents.uploadReviewEditId">{{ t.player_approve }}</button>
                                             </div>
                                         </div>
                                     </template>
 
                                     <template x-if="$store.torrents.uploadReleaseDraft">
                                         <div class="upload-editor-form">
-                                            <label class="upload-field upload-field-wide"><span>Album</span><input type="text" x-model="$store.torrents.uploadReleaseDraft.title"></label>
-                                            <label class="upload-field upload-field-wide"><span>Album artists</span><input type="text" x-model="$store.torrents.uploadReleaseDraft.artists"></label>
-                                            <label class="upload-field upload-field-half"><span>Year</span><input type="number" x-model="$store.torrents.uploadReleaseDraft.year"></label>
-                                            <label class="upload-field upload-field-half"><span>Type</span><select x-model="$store.torrents.uploadReleaseDraft.release_type"><option value="album">Album</option><option value="single">Single</option><option value="ep">EP</option><option value="compilation">Compilation</option><option value="mixtape">Mixtape</option><option value="live">Live</option><option value="soundtrack">Soundtrack</option><option value="remix">Remix</option><option value="demo">Demo</option></select></label>
-                                            <label class="upload-field upload-field-toggle"><input type="checkbox" x-model="$store.torrents.uploadReleaseDraft.is_hidden"><span>Hidden</span></label>
+                                            <label class="upload-field upload-field-wide"><span>{{ t.player_album }}</span><input type="text" x-model="$store.torrents.uploadReleaseDraft.title"></label>
+                                            <label class="upload-field upload-field-wide"><span>{{ t.player_album_artists }}</span><input type="text" x-model="$store.torrents.uploadReleaseDraft.artists"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_year }}</span><input type="number" x-model="$store.torrents.uploadReleaseDraft.year"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_type }}</span><select x-model="$store.torrents.uploadReleaseDraft.release_type"><option value="album">{{ t.player_release_type_album }}</option><option value="single">{{ t.player_release_type_single }}</option><option value="ep">{{ t.player_release_type_ep }}</option><option value="compilation">{{ t.player_release_type_compilation }}</option><option value="mixtape">{{ t.player_release_type_mixtape }}</option><option value="live">{{ t.player_release_type_live }}</option><option value="soundtrack">{{ t.player_release_type_soundtrack }}</option><option value="remix">{{ t.player_release_type_remix }}</option><option value="demo">{{ t.player_release_type_demo }}</option></select></label>
+                                            <label class="upload-field upload-field-toggle"><input type="checkbox" x-model="$store.torrents.uploadReleaseDraft.is_hidden"><span>{{ t.player_hidden }}</span></label>
                                             <div class="upload-editor-actions">
-                                                <button class="modal-btn modal-btn-primary" @click="$store.torrents.saveUploadReleaseEdit()" :disabled="$store.torrents.uploadReleaseSavingId === $store.torrents.uploadReleaseEditId">Save release</button>
+                                                <button class="modal-btn modal-btn-primary" @click="$store.torrents.saveUploadReleaseEdit()" :disabled="$store.torrents.uploadReleaseSavingId === $store.torrents.uploadReleaseEditId">{{ t.player_save_release }}</button>
                                             </div>
                                         </div>
                                     </template>
 
                                     <template x-if="$store.torrents.uploadDraft">
                                         <div class="upload-editor-form">
-                                            <label class="upload-field upload-field-wide"><span>Title</span><input type="text" x-model="$store.torrents.uploadDraft.title"></label>
-                                            <label class="upload-field upload-field-half"><span>Artists</span><input type="text" x-model="$store.torrents.uploadDraft.artists"></label>
-                                            <label class="upload-field upload-field-half"><span>Featured</span><input type="text" x-model="$store.torrents.uploadDraft.featured_artists"></label>
-                                            <label class="upload-field upload-field-half"><span>Album</span><input type="text" x-model="$store.torrents.uploadDraft.release_title"></label>
-                                            <label class="upload-field upload-field-half"><span>Type</span><select x-model="$store.torrents.uploadDraft.release_type"><option value="album">Album</option><option value="single">Single</option><option value="ep">EP</option><option value="compilation">Compilation</option><option value="mixtape">Mixtape</option><option value="live">Live</option><option value="soundtrack">Soundtrack</option><option value="remix">Remix</option><option value="demo">Demo</option></select></label>
-                                            <label class="upload-field upload-field-compact"><span>Year</span><input type="number" x-model="$store.torrents.uploadDraft.release_year"></label>
-                                            <label class="upload-field upload-field-compact"><span>Track #</span><input type="number" min="1" x-model="$store.torrents.uploadDraft.track_number"></label>
-                                            <label class="upload-field upload-field-compact"><span>Disc #</span><input type="number" min="1" x-model="$store.torrents.uploadDraft.disc_number"></label>
-                                            <label class="upload-field upload-field-toggle"><input type="checkbox" x-model="$store.torrents.uploadDraft.is_hidden"><span>Hidden</span></label>
+                                            <label class="upload-field upload-field-wide"><span>{{ t.player_title }}</span><input type="text" x-model="$store.torrents.uploadDraft.title"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_artists }}</span><input type="text" x-model="$store.torrents.uploadDraft.artists"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_featured }}</span><input type="text" x-model="$store.torrents.uploadDraft.featured_artists"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_album }}</span><input type="text" x-model="$store.torrents.uploadDraft.release_title"></label>
+                                            <label class="upload-field upload-field-half"><span>{{ t.player_type }}</span><select x-model="$store.torrents.uploadDraft.release_type"><option value="album">{{ t.player_release_type_album }}</option><option value="single">{{ t.player_release_type_single }}</option><option value="ep">{{ t.player_release_type_ep }}</option><option value="compilation">{{ t.player_release_type_compilation }}</option><option value="mixtape">{{ t.player_release_type_mixtape }}</option><option value="live">{{ t.player_release_type_live }}</option><option value="soundtrack">{{ t.player_release_type_soundtrack }}</option><option value="remix">{{ t.player_release_type_remix }}</option><option value="demo">{{ t.player_release_type_demo }}</option></select></label>
+                                            <label class="upload-field upload-field-compact"><span>{{ t.player_year }}</span><input type="number" x-model="$store.torrents.uploadDraft.release_year"></label>
+                                            <label class="upload-field upload-field-compact"><span>{{ t.player_track_number }}</span><input type="number" min="1" x-model="$store.torrents.uploadDraft.track_number"></label>
+                                            <label class="upload-field upload-field-compact"><span>{{ t.player_disc_number }}</span><input type="number" min="1" x-model="$store.torrents.uploadDraft.disc_number"></label>
+                                            <label class="upload-field upload-field-toggle"><input type="checkbox" x-model="$store.torrents.uploadDraft.is_hidden"><span>{{ t.player_hidden }}</span></label>
                                             <div class="upload-editor-actions">
-                                                <button class="modal-btn modal-btn-primary" @click="$store.torrents.saveUploadEdit()" :disabled="$store.torrents.uploadSavingId === $store.torrents.uploadEditId">Save track</button>
+                                                <button class="modal-btn modal-btn-primary" @click="$store.torrents.saveUploadEdit()" :disabled="$store.torrents.uploadSavingId === $store.torrents.uploadEditId">{{ t.player_save_track }}</button>
                                             </div>
                                         </div>
                                     </template>
@@ -526,7 +553,7 @@
                                             <div class="upload-track-main">
                                                 <div class="upload-track-title">
                                                     <span x-text="item.track.title"></span>
-                                                    <span class="upload-hidden-pill" x-show="item.is_hidden">hidden</span>
+                                                    <span class="upload-hidden-pill" x-show="item.is_hidden">{{ t.player_hidden }}</span>
                                                 </div>
                                                 <div class="upload-track-meta">
                                                     <span x-text="$store.torrents.uploadArtistsText(item)"></span>
@@ -543,7 +570,7 @@
                                                 <button class="track-action-btn queue-insert-btn queue-end-btn" @click="$store.queue.addToEnd([item.track])" title="{{ t.player_add_to_queue }}">
                                                     <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M5 6h14M5 12h14M5 18h7"/><path d="M17 15l4 3-4 3" fill="currentColor" stroke="none"/></svg>
                                                 </button>
-                                                <button class="modal-btn modal-btn-ghost" @click="$store.torrents.editUpload(item)">Edit</button>
+                                                <button class="modal-btn modal-btn-ghost" @click="$store.torrents.editUpload(item)">{{ t.player_edit }}</button>
                                             </div>
                                         </div>
                                     </template>
@@ -551,52 +578,52 @@
                                     <template x-if="$store.torrents.uploadEditId === item.track.id">
                                         <div class="upload-edit-form">
                                             <label>
-                                                <span>Title</span>
+                                                <span>{{ t.player_title }}</span>
                                                 <input type="text" x-model="$store.torrents.uploadDraft.title">
                                             </label>
                                             <label>
-                                                <span>Artists</span>
-                                                <input type="text" x-model="$store.torrents.uploadDraft.artists" placeholder="Artist, Featured Artist">
+                                                <span>{{ t.player_artists }}</span>
+                                                <input type="text" x-model="$store.torrents.uploadDraft.artists" placeholder="{{ t.player_artist_featured_placeholder }}">
                                             </label>
                                             <label>
-                                                <span>Release</span>
+                                                <span>{{ t.player_release }}</span>
                                                 <input type="text" x-model="$store.torrents.uploadDraft.release_title">
                                             </label>
                                             <label>
-                                                <span>Type</span>
+                                                <span>{{ t.player_type }}</span>
                                                 <select x-model="$store.torrents.uploadDraft.release_type">
-                                                    <option value="album">Album</option>
-                                                    <option value="single">Single</option>
-                                                    <option value="ep">EP</option>
-                                                    <option value="compilation">Compilation</option>
-                                                    <option value="mixtape">Mixtape</option>
-                                                    <option value="live">Live</option>
-                                                    <option value="soundtrack">Soundtrack</option>
-                                                    <option value="remix">Remix</option>
-                                                    <option value="demo">Demo</option>
+                                                    <option value="album">{{ t.player_release_type_album }}</option>
+                                                    <option value="single">{{ t.player_release_type_single }}</option>
+                                                    <option value="ep">{{ t.player_release_type_ep }}</option>
+                                                    <option value="compilation">{{ t.player_release_type_compilation }}</option>
+                                                    <option value="mixtape">{{ t.player_release_type_mixtape }}</option>
+                                                    <option value="live">{{ t.player_release_type_live }}</option>
+                                                    <option value="soundtrack">{{ t.player_release_type_soundtrack }}</option>
+                                                    <option value="remix">{{ t.player_release_type_remix }}</option>
+                                                    <option value="demo">{{ t.player_release_type_demo }}</option>
                                                 </select>
                                             </label>
                                             <label>
-                                                <span>Year</span>
+                                                <span>{{ t.player_year }}</span>
                                                 <input type="number" x-model="$store.torrents.uploadDraft.release_year">
                                             </label>
                                             <label>
-                                                <span>Track #</span>
+                                                <span>{{ t.player_track_number }}</span>
                                                 <input type="number" min="1" x-model="$store.torrents.uploadDraft.track_number">
                                             </label>
                                             <label>
-                                                <span>Disc #</span>
+                                                <span>{{ t.player_disc_number }}</span>
                                                 <input type="number" min="1" x-model="$store.torrents.uploadDraft.disc_number">
                                             </label>
                                             <label class="upload-hidden-toggle">
                                                 <input type="checkbox" x-model="$store.torrents.uploadDraft.is_hidden">
-                                                <span>Hidden</span>
+                                                <span>{{ t.player_hidden }}</span>
                                             </label>
                                             <div class="upload-edit-actions">
                                                 <button class="modal-btn modal-btn-primary"
                                                         @click="$store.torrents.saveUploadEdit()"
-                                                        :disabled="$store.torrents.uploadSavingId === item.track.id">Save</button>
-                                                <button class="modal-btn modal-btn-ghost" @click="$store.torrents.cancelUploadEdit()">Cancel</button>
+                                                        :disabled="$store.torrents.uploadSavingId === item.track.id">{{ t.player_save }}</button>
+                                                <button class="modal-btn modal-btn-ghost" @click="$store.torrents.cancelUploadEdit()">{{ t.player_cancel }}</button>
                                             </div>
                                         </div>
                                     </template>
@@ -609,6 +636,144 @@
         </div>
     </template>
 
+    <!-- User Settings Modal -->
+    <template x-if="$store.user.settingsOpen">
+        <div class="modal-overlay" @click.self="$store.user.closeSettings()">
+            <div class="modal-box user-settings-modal">
+                <div class="user-settings-head">
+                    <div>
+                        <h3>User settings</h3>
+                        <p>Personal services, listening history and trusted devices.</p>
+                    </div>
+                    <button class="mobile-list-action" @click="$store.user.closeSettings()" title="{{ t.player_close }}">
+                        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                            <line x1="18" y1="6" x2="6" y2="18"/>
+                            <line x1="6" y1="6" x2="18" y2="18"/>
+                        </svg>
+                    </button>
+                </div>
+
+                <section class="user-settings-section">
+                    <div class="user-settings-section-head">
+                        <div>
+                            <h4>Listening history</h4>
+                            <p>Review plays recorded by this web player.</p>
+                        </div>
+                        <button class="settings-secondary-btn" @click="$store.user.openHistoryFromSettings()">Open history</button>
+                    </div>
+                </section>
+
+                <section class="user-settings-section">
+                    <div class="user-settings-section-head">
+                        <div>
+                            <h4>Last.fm</h4>
+                            <p x-text="$store.user.lastfmStatusLabel()"></p>
+                        </div>
+                        <button class="settings-secondary-btn"
+                                :class="$store.user.lastfmClass()"
+                                :disabled="$store.user.lastfmBusy || !$store.user.lastfm?.configured"
+                                @click="$store.user.handleLastfm()"
+                                x-text="$store.user.lastfm?.connected && !$store.user.lastfm?.reauth_required ? 'Disconnect' : 'Connect'"></button>
+                    </div>
+                </section>
+
+                <section class="user-settings-section user-settings-devices">
+                    <div class="user-settings-section-head">
+                        <div>
+                            <h4>Connected devices</h4>
+                            <p x-text="$store.devices.fedSummary()"></p>
+                        </div>
+                        <button class="settings-secondary-btn"
+                                :disabled="$store.devices.fedBusy"
+                                @click="$store.devices.syncFedDevices()">Sync now</button>
+                    </div>
+                    <template x-if="$store.devices.fedError">
+                        <div class="fed-device-error" x-text="$store.devices.fedError"></div>
+                    </template>
+
+                    <div class="settings-device-group">
+                        <div class="settings-device-label">Web player sessions</div>
+                        <template x-for="device in $store.devices.webDevices()" :key="'settings-web-' + device.id">
+                            <div class="settings-device-row">
+                                <span class="device-row-icon">
+                                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                                        <rect x="3" y="4" width="18" height="12" rx="2"/>
+                                        <path d="M8 20h8M12 16v4"/>
+                                    </svg>
+                                </span>
+                                <span class="fed-device-main">
+                                    <span class="fed-device-name" x-text="device.name"></span>
+                                    <span class="fed-device-meta"
+                                          x-text="device.is_current ? 'This browser session' : (device.is_active ? 'Active web session' : 'Web session')"></span>
+                                </span>
+                            </div>
+                        </template>
+                    </div>
+
+                    <div class="settings-device-group">
+                        <div class="settings-device-label">Trusted federation devices</div>
+                        <template x-for="request in $store.devices.fedPending()" :key="request.request_id">
+                            <div class="fed-pairing-card">
+                                <div class="fed-pairing-title" x-text="request.name || request.device_id"></div>
+                                <div class="fed-pairing-meta"
+                                     x-text="request.requester_group_id ? 'Already belongs to another sync group' : (request.client_version || 'Waiting for approval')"></div>
+                                <div class="fed-device-actions">
+                                    <button class="fed-action-btn primary"
+                                            @click="$store.devices.answerFedPairing(request, true, !!request.requester_group_id)"
+                                            x-text="request.requester_group_id ? 'Use existing group' : 'Approve'"></button>
+                                    <button class="fed-action-btn"
+                                            @click="$store.devices.answerFedPairing(request, false, false)">Reject</button>
+                                </div>
+                            </div>
+                        </template>
+                        <template x-for="device in $store.devices.fedDevices()" :key="'settings-fed-' + device.device_id">
+                            <div class="settings-device-row federation">
+                                <span class="device-row-icon federation-device-icon">
+                                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8">
+                                        <circle cx="12" cy="12" r="3"/>
+                                        <path d="M5.6 8.5a7.5 7.5 0 000 7M18.4 8.5a7.5 7.5 0 010 7"/>
+                                        <path d="M2.8 5.8a11 11 0 000 12.4M21.2 5.8a11 11 0 010 12.4"/>
+                                    </svg>
+                                </span>
+                                <span class="fed-device-main">
+                                    <span class="fed-device-name" x-text="device.name || device.device_id"></span>
+                                    <span class="fed-device-meta"
+                                          x-text="device.is_self ? 'This web player' : (device.client_version || 'Trusted device')"></span>
+                                </span>
+                                <button class="fed-revoke-btn"
+                                        x-show="!device.is_self"
+                                        :disabled="$store.devices.fedBusy"
+                                        @click="$store.devices.revokeFedDevice(device)">Revoke</button>
+                            </div>
+                        </template>
+                    </div>
+
+                    <div class="settings-pairing-actions">
+                        <button class="settings-primary-btn"
+                                :disabled="$store.devices.fedBusy"
+                                @click="$store.devices.generateFedInvite()">Invite a device</button>
+                        <template x-if="$store.devices.fedInvite">
+                            <input class="fed-device-input"
+                                   readonly
+                                   :value="$store.devices.fedInvite"
+                                   @focus="$event.target.select()">
+                        </template>
+                        <div class="fed-connect-row">
+                            <input class="fed-device-input"
+                                   type="text"
+                                   placeholder="Paste frid:// invite"
+                                   x-model="$store.devices.fedInviteInput"
+                                   @keydown.enter.prevent="$store.devices.connectFedInvite()">
+                            <button class="settings-secondary-btn"
+                                    :disabled="$store.devices.fedBusy || !$store.devices.fedInviteInput.trim()"
+                                    @click="$store.devices.connectFedInvite()">Connect</button>
+                        </div>
+                    </div>
+                </section>
+            </div>
+        </div>
+    </template>
+
     <!-- Play History Modal -->
     <template x-if="$store.history.modal">
         <div class="modal-overlay" @click.self="$store.history.close()">
@@ -656,7 +821,12 @@
                                 </template>
                             </button>
                             <div class="track-info">
-                                <div class="track-title" x-text="item.track?.title || item.track_title"></div>
+                                <div class="track-title">
+                                    <span x-text="item.track?.title || item.track_title"></span>
+                                    <span class="history-device-badge"
+                                          :title="item.device_id"
+                                          x-text="item.device_name"></span>
+                                </div>
                                 <div class="track-artists-inline">
                                     <template x-for="(artist, artistIdx) in $store.library.trackArtistLinks(item.track)" :key="artist.label + '-' + artist.id + '-' + artistIdx">
                                         <span>
@@ -695,6 +865,9 @@
                                 <button class="track-action-btn queue-insert-btn queue-end-btn" @click.stop="$store.queue.addToEnd([item.track])" title="{{ t.player_add_to_queue }}">
                                     <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M5 6h14M5 12h14M5 18h7"/><path d="M17 15l4 3-4 3" fill="currentColor" stroke="none"/></svg>
                                 </button>
+                                <button class="track-action-btn track-share-btn" @click.stop="$store.sharing.copyTrack(item.track || item.track_id, $event.currentTarget)" title="{{ t.player_share_track }}" aria-label="{{ t.player_share_track }}">
+                                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><circle cx="18" cy="5" r="3"/><circle cx="6" cy="12" r="3"/><circle cx="18" cy="19" r="3"/><path d="M8.6 10.6l6.8-3.9M8.6 13.4l6.8 3.9"/></svg>
+                                </button>
                                 <button class="track-action-btn playlist-add-btn" @click.stop="$store.playlists.showPicker([item.track_id])" title="{{ t.player_add_to_playlist }}">
                                     <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M8 6h13M8 12h13M8 18h13M3 6h.01M3 12h.01M3 18h.01"/></svg>
                                 </button>