fix: audio in verify_sync

verify_sync.py

@@ -140,6 +140,7 @@ def apply_dark_theme(app: QtWidgets.QApplication):
 class AudioPlayer:
     def __init__(self):
         self.playing = False
+        self._stream = None
         self._lock = threading.Lock()
 
     def play(self, data: np.ndarray, sr: int):
@@ -149,7 +150,7 @@ class AudioPlayer:
             sd.stop()
             self.playing = True
             try:
-                sd.play(data, samplerate=sr, blocking=False)
+                self._stream = sd.play(data, samplerate=sr, blocking=False)
             except Exception as e:
                 print(f"audio play error: {e}", file=sys.stderr)
                 self.playing = False
@@ -158,6 +159,7 @@ class AudioPlayer:
         if HAS_SD:
             with self._lock:
                 sd.stop()
+                self._stream = None
                 self.playing = False