[打断入口修复]：完成播报打断启动条件修正，包含去除实时转写硬依赖和回归测试

src/owner_voice_pet/assistant_pipeline.py

@@ -560,7 +560,6 @@ class TurnController:
         return (
             segment is not None
             and self.config.barge_in_enabled
-            and self.realtime_stt is not None
             and segment.duration_ms > self.config.barge_in_echo_guard_ms
         )
 

tests/test_live_runtime.py

@@ -749,7 +749,7 @@ class LiveRuntimeTests(unittest.TestCase):
             wakeword=KeywordWakeWordProvider(),
             vad_recorder=VadRecorder(EnergyVadProvider(), min_duration_ms=40, end_silence_ms=40),
             stt=stt,
-            realtime_stt=MetadataSttProvider(),
+            realtime_stt=None,
             llm=llm,
             tts=SineTtsProvider(),
             context=ConversationContext(),