feat: real-time logs window + v1.3

Add AppLogger singleton (ring buffer, 500 lines) and LogsView with
auto-scroll and color-coded output. Button in Settings opens a resizable
logs window. Log track start, device active changes, and network errors.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

furumi_macos.xcodeproj/project.pbxproj

@@ -409,7 +409,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
-				MARKETING_VERSION = 1.2;
+				MARKETING_VERSION = 1.3;
 				PRODUCT_BUNDLE_IDENTIFIER = "hexor.furumi-macos";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				REGISTER_APP_GROUPS = YES;
@@ -442,7 +442,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
-				MARKETING_VERSION = 1.2;
+				MARKETING_VERSION = 1.3;
 				PRODUCT_BUNDLE_IDENTIFIER = "hexor.furumi-macos";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				REGISTER_APP_GROUPS = YES;

furumi_macos/AppLogger.swift

@@ -0,0 +1,36 @@
+//
+//  AppLogger.swift
+//  furumi_macos
+//
+
+import Foundation
+import Observation
+
+@MainActor
+@Observable
+final class AppLogger {
+    static let shared = AppLogger()
+
+    private(set) var lines: [String] = []
+    private let maxLines = 500
+
+    private init() {}
+
+    func log(_ message: String) {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "HH:mm:ss.SSS"
+        let timestamp = formatter.string(from: Date())
+        lines.append("[\(timestamp)] \(message)")
+        if lines.count > maxLines {
+            lines.removeFirst(lines.count - maxLines)
+        }
+    }
+
+    func clear() {
+        lines.removeAll()
+    }
+}
+
+func appLog(_ message: String) {
+    Task { @MainActor in AppLogger.shared.log(message) }
+}

furumi_macos/ContentView.swift

@@ -107,11 +107,13 @@ struct ContentView: View {
         deviceManager.start(service: service, player: player)
         let am = authManager
         player.onTrackStarted = { trackId in
-            try? await am.catalogService?.lastfmNowPlaying(trackId: trackId)
+            do { try await am.catalogService?.lastfmNowPlaying(trackId: trackId) }
+            catch { appLog("❌ lastfm now-playing error: \(error)") }
         }
         player.onTrackFinished = { trackId, startedAt, durationListened, completed in
             guard let svc = am.catalogService else { return }
-            try? await svc.recordHistory(trackId: trackId, startedAt: startedAt, durationListened: durationListened, completed: completed)
+            do { try await svc.recordHistory(trackId: trackId, startedAt: startedAt, durationListened: durationListened, completed: completed) }
+            catch { appLog("❌ history record error: \(error)") }
         }
         let gvm = globalVM
         Task { await gvm?.loadFirstPage() }

furumi_macos/DeviceManager.swift

@@ -94,7 +94,9 @@ final class DeviceManager {
             )
             let response = try decoder.decode(DevicePollResponseDTO.self, from: data)
             applyPollResponse(response, player: player)
-        } catch { }
+        } catch {
+            appLog("❌ Device poll error: \(error)")
+        }
     }
 
     private func applyPollResponse(_ response: DevicePollResponseDTO, player: PlayerManager) {
@@ -104,10 +106,11 @@ final class DeviceManager {
         activeDeviceId = response.activeDeviceId
 
         if isThisDeviceActive {
+            if !wasActive { appLog("📱 This device became active") }
             remoteState = nil
         } else {
+            if wasActive { appLog("📱 This device became inactive, active: \(response.activeDeviceId ?? "none")") }
             remoteState = response.playbackState
-            // Pause local playback when this device is no longer active
             if wasActive {
                 player.pauseIfNeeded()
             }

furumi_macos/LogsView.swift

@@ -0,0 +1,66 @@
+//
+//  LogsView.swift
+//  furumi_macos
+//
+
+import SwiftUI
+
+struct LogsView: View {
+    @State private var logger = AppLogger.shared
+
+    var body: some View {
+        VStack(spacing: 0) {
+            HStack {
+                Text("Logs")
+                    .font(.headline)
+                Spacer()
+                Text("\(logger.lines.count) lines")
+                    .font(.caption)
+                    .foregroundColor(.secondary)
+                Button("Clear") { logger.clear() }
+                    .buttonStyle(.bordered)
+                    .controlSize(.small)
+            }
+            .padding(.horizontal, 12)
+            .padding(.vertical, 8)
+
+            Divider()
+
+            ScrollViewReader { proxy in
+                ScrollView {
+                    LazyVStack(alignment: .leading, spacing: 0) {
+                        ForEach(Array(logger.lines.enumerated()), id: \.offset) { idx, line in
+                            Text(line)
+                                .font(.system(size: 11, design: .monospaced))
+                                .foregroundColor(color(for: line))
+                                .textSelection(.enabled)
+                                .frame(maxWidth: .infinity, alignment: .leading)
+                                .padding(.horizontal, 10)
+                                .padding(.vertical, 1)
+                                .id(idx)
+                        }
+                    }
+                    .padding(.vertical, 4)
+                }
+                .onChange(of: logger.lines.count) { _, _ in
+                    if let last = logger.lines.indices.last {
+                        proxy.scrollTo(last, anchor: .bottom)
+                    }
+                }
+                .onAppear {
+                    if let last = logger.lines.indices.last {
+                        proxy.scrollTo(last, anchor: .bottom)
+                    }
+                }
+            }
+        }
+        .frame(width: 680, height: 420)
+    }
+
+    private func color(for line: String) -> Color {
+        if line.contains("error") || line.contains("Error") || line.contains("❌") { return .red }
+        if line.contains("warn") || line.contains("Warn") || line.contains("⚠️") { return .orange }
+        if line.contains("▶") { return .accentColor }
+        return .primary
+    }
+}

furumi_macos/PlayerManager.swift

@@ -97,6 +97,7 @@ final class PlayerManager {
         player?.play()
         isPlaying = true
         currentTrack = track
+        appLog("▶ \(track.title) — \(track.artistNames)")
         currentTime = 0
         duration = Double(track.durationSeconds)
         trackStartedAt = Date()

furumi_macos/SettingsView.swift

@@ -18,6 +18,17 @@ struct SettingsView: View {
             Divider()
             authSection
             Spacer()
+            Divider()
+            HStack {
+                Spacer()
+                Button {
+                    NSApp.sendAction(#selector(AppDelegate.openLogs), to: nil, from: nil)
+                } label: {
+                    Label("View Logs", systemImage: "doc.text.magnifyingglass")
+                }
+                .buttonStyle(.bordered)
+                .controlSize(.small)
+            }
         }
         .padding(24)
         .frame(width: 360)

furumi_macos/furumi_macosApp.swift

@@ -19,6 +19,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
     var statusItem: NSStatusItem!
     var popover: NSPopover!
     var settingsWindow: NSWindow?
+    var logsWindow: NSWindow?
     let authManager = AuthManager()
 
     func applicationDidFinishLaunching(_ notification: Notification) {
@@ -108,6 +109,29 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         NSApp.activate(ignoringOtherApps: true)
     }
 
+    @objc func openLogs() {
+        if let window = logsWindow {
+            window.makeKeyAndOrderFront(nil)
+            NSApp.activate(ignoringOtherApps: true)
+            return
+        }
+
+        let window = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 680, height: 420),
+            styleMask: [.titled, .closable, .resizable],
+            backing: .buffered,
+            defer: false
+        )
+        window.title = "Logs"
+        window.contentViewController = NSHostingController(rootView: LogsView())
+        window.center()
+        window.isReleasedWhenClosed = false
+        logsWindow = window
+
+        window.makeKeyAndOrderFront(nil)
+        NSApp.activate(ignoringOtherApps: true)
+    }
+
     @objc func quit() {
         NSApplication.shared.terminate(nil)
     }