fix argument error in send_audio

app.py

@@ -108,7 +108,7 @@ def main(input_audio):
             response = agent.respond(transcript)
             logger.info(f"Agent response: {response}")
             output_audio = synthesizer.synthesize(response)
-            return SpeakerOutput.send_audio(output_audio)
+            return SpeakerOutput.send_audio(audio_segment=output_audio)
 
         except Exception as e:
             logger.error("Failed to synthesize response: %s", e)