Add support for Xfyun ASR and TTS services in the backend

- Introduce new Xfyun ASR and TTS services, enabling integration with iFlytek's voice recognition and synthesis capabilities.
- Update AssistantConfig model to include interface types for STT and TTS.
- Enhance credential testing to validate Xfyun credentials.
- Modify service factory to create Xfyun services based on configuration.
- Update README with new configuration details for Xfyun integration.
- Add new frontend components for visualizing audio streams and managing user interactions.

backend/services/pipecat/transports.py

@@ -11,14 +11,13 @@
 from fastapi import WebSocket
 
 from pipecat.transports.base_transport import TransportParams
-from pipecat.audio.vad.silero import SileroVADAnalyzer
 
 # WebRTC
 from pipecat.transports.smallwebrtc.connection import SmallWebRTCConnection
 from pipecat.transports.smallwebrtc.transport import SmallWebRTCTransport
 
 # 裸 WS 音频流
-from pipecat.transports.network.fastapi_websocket import (
+from pipecat.transports.websocket.fastapi import (
     FastAPIWebsocketTransport,
     FastAPIWebsocketParams,
 )
@@ -30,7 +29,6 @@ def _base_params() -> dict:
     return dict(
         audio_in_enabled=True,
         audio_out_enabled=True,
-        vad_analyzer=SileroVADAnalyzer(),  # 本地 VAD,打断功能依赖它
     )