feat(agent): add voice message support with TTS/STT for Telegram and WeChat

- Integrate voice message handling: detect and extract audio references from Telegram and WeChat messages, route to agent with voice reply preference.
- Add voice provider abstraction and OpenAI-based TTS/STT implementation.
- Implement agent tool `send_voice_message` for generating and sending voice replies, with fallback to text if voice is unavailable.
- Extend agent prompt and context to support voice reply instructions.
- Update notification and message schemas to support audio fields.
- Add Telegram and WeChat voice sending logic, including audio file conversion and temporary media upload for WeChat.
- Add tests for voice helper and agent voice routing.

app/agent/tools/base.py

@@ -31,6 +31,7 @@ class MoviePilotTool(BaseTool, metaclass=ABCMeta):
     _username: Optional[str] = PrivateAttr(default=None)
     _stream_handler: Optional[StreamingHandler] = PrivateAttr(default=None)
     _require_admin: bool = PrivateAttr(default=False)
+    _agent_context: dict = PrivateAttr(default_factory=dict)
 
     def __init__(self, session_id: str, user_id: str, **kwargs):
         super().__init__(**kwargs)
@@ -142,6 +143,12 @@ class MoviePilotTool(BaseTool, metaclass=ABCMeta):
         """
         self._stream_handler = stream_handler
 
+    def set_agent_context(self, agent_context: Optional[dict]):
+        """
+        设置与当前 Agent 共享的上下文。
+        """
+        self._agent_context = agent_context or {}
+
     async def _check_permission(self) -> Optional[str]:
         """
         检查用户权限：