feat(voice-client): 双层配置持久化、精简手术号 UI 与 WS/服务端排查日志

- machine_config：系统级 + 用户级 voice_client.json 合并，界面失焦保存至用户目录
- 移除「当前手术号」表单项与占位文案；指派后仅在窗口标题显示手术号
- WebSocket 连接日志附带绑定/开录路径排查说明
- 开录未推送时服务端 WARNING（无站点绑定或 camera_ids 不匹配）
- 测试、README、.env.example 同步

Made-with: Cursor

app/services/voice_terminal_hub.py

@@ -29,11 +29,17 @@ async def assign_voice_terminal_after_recording_started(
         await hub.notify_start(voice_tid, surgery_id)
     elif hub.bindings is not None:
         logger.warning(
-            "voice or room bindings have no camera set matching start "
+            "开录未向任何语音终端推送：camera_ids 与 OR_SITE_CONFIG「voice_or_room_bindings」无匹配 "
             "surgery_id={} camera_ids={}",
             surgery_id,
             camera_ids,
         )
+    else:
+        logger.warning(
+            "开录未推送语音终端：未加载 OR_SITE_CONFIG 或 voice_or_room_bindings 为空；"
+            "桌面端 WebSocket 不会收到 voice_assignment surgery_id={}",
+            surgery_id,
+        )
 
 
 class VoiceTerminalHub: