feat(auth): replace cookie/api-key auth with JWT Bearer tokens, separate UI from API

- Add JWT Bearer token validation to Rust API via OIDC provider JWKS
  with automatic key rotation and 1-hour cache
- Remove x-api-key auth support and built-in web UI from furumi-web-player,
  leaving it as a pure API server
- Add /auth/token endpoint to Node player server to expose OIDC access
  tokens to the frontend
- Move Node player auth endpoints from /api/* to /auth/* to avoid
  path conflicts with Rust API
- Add static file serving to Node Express server for production
  single-container deployment
- Fix SameSite=Strict cookie issue breaking OIDC redirect flow (use Lax)
- Add Dockerfile.node-player with multi-stage Node.js build
- Add CI workflows for node-player Docker image (dev + release)
- Optimize Rust Dockerfiles with dependency caching layer
- Update docker-compose with OIDC env vars and OLLAMA_MODEL support
- Cherry-pick agent LLM client fixes from DEV branch

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker/Dockerfile.agent

@@ -8,8 +8,35 @@ RUN apt-get update && apt-get install -y \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /usr/src/app
+
+# 1. Copy workspace manifests and lock file (changes rarely → cached layer)
+COPY Cargo.toml Cargo.lock ./
+COPY furumi-common/Cargo.toml furumi-common/Cargo.toml
+COPY furumi-server/Cargo.toml furumi-server/Cargo.toml
+COPY furumi-client-core/Cargo.toml furumi-client-core/Cargo.toml
+COPY furumi-mount-linux/Cargo.toml furumi-mount-linux/Cargo.toml
+COPY furumi-mount-macos/Cargo.toml furumi-mount-macos/Cargo.toml
+COPY furumi-agent/Cargo.toml furumi-agent/Cargo.toml
+COPY furumi-web-player/Cargo.toml furumi-web-player/Cargo.toml
+
+# 2. Create dummy sources so cargo can resolve and build dependencies
+RUN mkdir -p furumi-common/src && echo "pub fn _dummy(){}" > furumi-common/src/lib.rs \
+    && mkdir -p furumi-server/src && echo "fn main(){}" > furumi-server/src/main.rs \
+    && mkdir -p furumi-client-core/src && echo "pub fn _dummy(){}" > furumi-client-core/src/lib.rs \
+    && mkdir -p furumi-mount-linux/src && echo "fn main(){}" > furumi-mount-linux/src/main.rs \
+    && mkdir -p furumi-mount-macos/src && echo "fn main(){}" > furumi-mount-macos/src/main.rs \
+    && mkdir -p furumi-agent/src && echo "fn main(){}" > furumi-agent/src/main.rs \
+    && mkdir -p furumi-web-player/src && echo "fn main(){}" > furumi-web-player/src/main.rs
+
+# 3. Build dependencies only (this layer is cached until Cargo.toml/lock change)
+RUN cargo build --release --bin furumi-agent 2>/dev/null || true
+
+# 4. Copy real source code
 COPY . .
 
+# 5. Touch sources to invalidate cargo's fingerprint for our crates (not deps)
+RUN touch furumi-common/src/lib.rs furumi-agent/src/main.rs
+
 ARG FURUMI_VERSION=dev
 RUN FURUMI_VERSION=${FURUMI_VERSION} cargo build --release --bin furumi-agent