[结束提示音]：完成对话结束音效提示，包含本地短音生成、恢复待机播放和配置测试

tests/test_pipeline_llm_tts.py

@@ -12,7 +12,7 @@ from owner_voice_pet.models import AudioFrame, ErrorCode, Message, PipelineState
 from owner_voice_pet.pipeline import VoicePipeline
 from owner_voice_pet.stt import MetadataSttProvider
 from owner_voice_pet.transport import MemoryAudioTransport
-from owner_voice_pet.tts import CloudTtsProvider, SentenceBuffer, SineTtsProvider, sanitize_tts_text
+from owner_voice_pet.tts import CloudTtsProvider, SentenceBuffer, SineTtsProvider, make_prompt_chime, sanitize_tts_text
 from owner_voice_pet.vad import EnergyVadProvider, VadRecorder
 from owner_voice_pet.wakeword import KeywordWakeWordProvider
 
@@ -73,6 +73,13 @@ class PipelineLlmTtsTests(unittest.TestCase):
         self.assertGreater(len(segment.pcm), 0)
         self.assertGreater(segment.duration_ms, 0)
 
+    def test_prompt_chime_generates_short_pcm_audio(self) -> None:
+        segment = make_prompt_chime(frequency_hz=880, duration_ms=140, sample_rate=16000, channels=1)
+
+        self.assertEqual(segment.duration_ms, 140)
+        self.assertEqual(segment.metadata["chime"], "end")
+        self.assertGreater(len(segment.pcm), 0)
+
     def test_cloud_tts_posts_speech_request(self) -> None:
         class FakeResponse:
             def __enter__(self):