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/prompt/__init__.py

@@ -50,10 +50,13 @@ class PromptManager:
             logger.error(f"加载提示词失败: {prompt_name}, 错误: {e}")
             raise
 
-    def get_agent_prompt(self, channel: str = None) -> str:
+    def get_agent_prompt(
+        self, channel: str = None, prefer_voice_reply: bool = False
+    ) -> str:
         """
         获取智能体提示词
         :param channel: 消息渠道（Telegram、微信、Slack等）
+        :param prefer_voice_reply: 是否优先使用语音回复
         :return: 提示词内容
         """
         # 基础提示词
@@ -87,12 +90,16 @@ class PromptManager:
 
         # MoviePilot系统信息
         moviepilot_info = self._get_moviepilot_info()
+        voice_reply_spec = self._generate_voice_reply_instructions(
+            prefer_voice_reply=prefer_voice_reply
+        )
 
         # 始终替换占位符，避免后续 .format() 时因残留花括号报 KeyError
         base_prompt = base_prompt.format(
             markdown_spec=markdown_spec,
             verbose_spec=verbose_spec,
             moviepilot_info=moviepilot_info,
+            voice_reply_spec=voice_reply_spec,
         )
 
         return base_prompt
@@ -166,6 +173,20 @@ class PromptManager:
             instructions.append("- Links: Paste URLs directly as text.")
         return "\n".join(instructions)
 
+    @staticmethod
+    def _generate_voice_reply_instructions(prefer_voice_reply: bool) -> str:
+        if not prefer_voice_reply:
+            return (
+                "- Voice replies: Use normal text replies by default. "
+                "Only call `send_voice_message` when spoken playback is clearly better than plain text."
+            )
+        return (
+            "- Current message context: The user sent a voice message.\n"
+            "- Reply preference: Prioritize calling `send_voice_message` for the main user-facing reply.\n"
+            "- Fallback: If voice is unavailable on the current channel, `send_voice_message` will fall back to text.\n"
+            "- Do not repeat the same full reply again after calling `send_voice_message`."
+        )
+
     def clear_cache(self):
         """
         清空缓存