[异步播报打断]：完成播放中麦克风监听和音色隔离，包含后台监听、助手回放抑制和用户音色打断测试

tests/test_transport.py

@@ -133,6 +133,21 @@ class TransportTests(unittest.TestCase):
         self.assertGreater(len(fake.output_writes), 1)
         self.assertEqual(callbacks[-1], result.duration_ms)
 
+    def test_sounddevice_chunk_playback_stops_on_signal(self) -> None:
+        fake = FakeSoundDevice()
+        transport = SoundDeviceAudioTransport(sounddevice_module=fake)
+        segment = AudioSegment(b"\x00\x00" * 1600, 16000, 1, 0, 100)
+
+        result = transport.play_pcm_chunks(
+            segment,
+            chunk_ms=20,
+            should_stop=lambda: len(fake.output_writes) >= 2,
+        )
+
+        self.assertTrue(result.played)
+        self.assertEqual(len(fake.output_writes), 2)
+        self.assertEqual(result.duration_ms, 40)
+
     def test_sounddevice_device_report_uses_query_devices(self) -> None:
         fake = FakeSoundDevice()
         report = SoundDeviceAudioTransport(sounddevice_module=fake).device_report()