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/synthetic_rtsp.py

@@ -6,7 +6,6 @@ process is gone — reconnect or re-orchestrate for another playthrough.
 
 from __future__ import annotations
 
-import json
 import os
 import shutil
 import socket
@@ -222,25 +221,3 @@ class SyntheticRtspManager:
 
         self._active = run
         return run, url_map
-
-
-def write_rtsp_url_json_file(
-    path: Path,
-    url_map: dict[str, str],
-    *,
-    replace_host: str,
-) -> None:
-    """Write JSON map; replace 127.0.0.1 in values with `replace_host` (e.g. host.docker.internal)."""
-    if replace_host in ("", "127.0.0.1"):
-        out = url_map
-    else:
-        out = {
-            k: v.replace("127.0.0.1", replace_host, 1)
-            for k, v in url_map.items()
-        }
-    path.parent.mkdir(parents=True, exist_ok=True)
-    text = json.dumps(out, ensure_ascii=False, indent=2, sort_keys=True) + "\n"
-    temp = path.with_name(path.name + ".tmp")
-    temp.write_text(text, encoding="utf-8")
-    temp.replace(path)
-    logger.info("Wrote RTSP map to {}", path)