[实时字幕端点]：完成无新文字快速结束录音，包含1.5秒停滞配置、Capture端点和回归测试

src/owner_voice_pet/vad.py

@@ -283,6 +283,9 @@ class VadRecorder:
         self.provider.reset()
         return segment
 
+    def finish(self, end_reason: str) -> AudioSegment:
+        return self._build_segment(end_reason)
+
 
 @dataclass(slots=True)
 class PrimarySpeakerVadRecorder(VadRecorder):