[真实链路自测]：完成完整流程自测和ACK缓冲修正，包含真实Provider验收、播放回声清理和回归测试

src/owner_voice_pet/simulation.py

@@ -55,7 +55,7 @@ class SimulationReporter:
 
 class BoundedMemoryAudioTransport(MemoryAudioTransport):
     def __init__(self, frames: list[AudioFrame], *, max_empty_reads: int = 5) -> None:
-        super().__init__(frames)
+        super().__init__(frames, flush_clears_input=False)
         self.max_empty_reads = max_empty_reads
         self.empty_reads = 0