fix(test): update play_beep test to match polling-based implementation

play_beep was changed from sd.wait() to a poll loop + sd.stop() in
302e1fe but the test was not updated. Now asserts sd.stop() instead
of sd.wait().

tests/tools/test_voice_mode.py

@@ -438,10 +438,15 @@ class TestPlayBeep:
 
         from tools.voice_mode import play_beep
 
+        # play_beep uses polling (get_stream) + sd.stop() instead of sd.wait()
+        mock_stream = MagicMock()
+        mock_stream.active = False
+        mock_sd.get_stream.return_value = mock_stream
+
         play_beep(frequency=880, duration=0.1, count=1)
 
         mock_sd.play.assert_called_once()
-        mock_sd.wait.assert_called_once()
+        mock_sd.stop.assert_called()
         # Verify audio data is int16 numpy array
         audio_arg = mock_sd.play.call_args[0][0]
         assert audio_arg.dtype == np.int16