feat(UI): display recording duration in real-time

Sources/VoiceMemo/AudioRecorder.swift

@@ -10,6 +10,7 @@ class AudioRecorder: NSObject, ObservableObject, SCStreamOutput, SCStreamDelegat
     @Published var availableApps: [SCRunningApplication] = []
     @Published var selectedApp: SCRunningApplication?
     @Published var latestTask: MeetingTask?
+    @Published var recordingDuration: TimeInterval = 0
 
     var lastUploadedURL: URL? {
         if let urlStr = latestTask?.ossUrl {
@@ -19,6 +20,7 @@ class AudioRecorder: NSObject, ObservableObject, SCStreamOutput, SCStreamDelegat
     }
 
     private var notificationObserver: NSObjectProtocol?
+    private var timer: Timer?
 
     private var settings: SettingsStore
     private var recordingId: String?
@@ -115,6 +117,14 @@ class AudioRecorder: NSObject, ObservableObject, SCStreamOutput, SCStreamDelegat
         isFirstRemoteBuffer = true
         isFirstMicBuffer = true
         self.recordingStartTime = Date()
+        self.recordingDuration = 0
+
+        DispatchQueue.main.async {
+            self.timer = Timer.scheduledTimer(withTimeInterval: 0.5, repeats: true) { [weak self] _ in
+                guard let self = self, let startTime = self.recordingStartTime else { return }
+                self.recordingDuration = Date().timeIntervalSince(startTime)
+            }
+        }
 
         // Generate URLs
         let formatter = DateFormatter()
@@ -323,6 +333,11 @@ class AudioRecorder: NSObject, ObservableObject, SCStreamOutput, SCStreamDelegat
 
     func stopRecording() {
         Task {
+            await MainActor.run {
+                self.timer?.invalidate()
+                self.timer = nil
+            }
+
             settings.log("Stop recording")
             // 1. Stop System Audio
             try? await stream?.stopCapture()

Sources/VoiceMemo/Views/RecordingView.swift

@@ -150,9 +150,10 @@ struct RecordingView: View {
                         HStack(spacing: 8) {
                             Image(systemName: "stop.fill")
                                 .font(.title3)
-                            Text("Stop Recording")
+                            Text("Stop Recording (\(formatDuration(recorder.recordingDuration)))")
                                 .font(.headline)
                                 .fontWeight(.bold)
+                                .monospacedDigit()
                         }
                         .foregroundColor(.white)
                         .padding(.vertical, 10)
@@ -198,4 +199,12 @@ struct RecordingView: View {
         }
         .background(Color(nsColor: .windowBackgroundColor)) // Light gray background
     }
+
+    private func formatDuration(_ duration: TimeInterval) -> String {
+        let formatter = DateComponentsFormatter()
+        formatter.allowedUnits = [.minute, .second]
+        formatter.unitsStyle = .positional
+        formatter.zeroFormattingBehavior = .pad
+        return formatter.string(from: duration) ?? "00:00"
+    }
 }