Fix debounce race and recorder callback write handling

app.go

@@ -149,11 +149,15 @@ var lastToggleUnixNano int64
 func (a *App) ToggleRecording() {
 	// Debounce toggle calls to prevent rapid firing from double-binds or Wayland glitches
 	now := time.Now().UnixNano()
+	for {
 		last := atomic.LoadInt64(&lastToggleUnixNano)
 		if last != 0 && time.Duration(now-last) < 500*time.Millisecond {
 			return
 		}
-	atomic.StoreInt64(&lastToggleUnixNano, now)
+		if atomic.CompareAndSwapInt64(&lastToggleUnixNano, last, now) {
+			break
+		}
+	}
 
 	if atomic.LoadInt32(&a.recording) == 1 {
 		a.StopRecording()

internal/audio/recorder/recorder.go

@@ -254,8 +254,15 @@ func (r *AudioRecorder) Cleanup() {
 
 // onAudioData is called by miniaudio when audio data is available.
 func (r *AudioRecorder) onAudioData(_, inputSamples []byte, _ uint32) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
 	if r.outputFile != nil && len(inputSamples) > 0 {
-		n, _ := r.outputFile.Write(inputSamples)
+		n, err := r.outputFile.Write(inputSamples)
+		if err != nil {
+			logger.Error("Failed to write audio data: %v", err)
+			return
+		}
 		r.dataSize += uint32(n)
 
 		// Calculate volume if callback is set