feat: 站点 JSON、语音终端 WebSocket 指派与客户端联调

- 用 OR_SITE_CONFIG_JSON_FILE 统一术间配置（video_rtsp_urls + voice_or_room_bindings）
- VoiceTerminalHub：assignment、WS 推送与 HTTP 查询；开录/停录后 notify
- 一键联调 orchestrate-and-start 与 /client/surgeries/start 共用指派逻辑，修复 demo 路径不发 WS
- 语音桌面端：SIGINT 退出、shutdown 清理、仅 WS 指派、固定 pending 轮询间隔、界面仅保留录音时长
- 新增/调整契约与绑定测试，文档与示例配置同步

Made-with: Cursor

app/services/surgery_pipeline.py

@@ -77,13 +77,16 @@ class SurgeryPipeline:
                 f"开录未能确认：{exc}",
             ) from exc
 
-    async def stop_recording(self, surgery_id: str) -> None:
-        """停止该手术关联的摄像头录制。仅在确认已全部停录时返回。"""
+    async def stop_recording(self, surgery_id: str) -> str | None:
+        """停止该手术关联的摄像头录制。仅在确认已全部停录时返回。返回绑定的语音终端 ID（若有）。"""
         try:
-            await self._sessions.stop_surgery(surgery_id, require_active=True)
+            return await self._sessions.stop_surgery(surgery_id, require_active=True)
         except SurgeryPipelineError:
             raise
 
+    def set_voice_terminal_id(self, surgery_id: str, terminal_id: str | None) -> None:
+        self._sessions.set_voice_terminal_id(surgery_id, terminal_id)
+
     async def get_consumption_details_for_client(
         self,
         surgery_id: str,