feat(video): 可配置 RTSP 打开超时并提高默认时长

- Settings 增加 video_open_timeout_sec（VIDEO_OPEN_TIMEOUT_SEC），默认 45s
- SessionManager 全部就绪等待为该值 + 5s；StreamWorker 传入单路超时
- baked pipeline 回退默认值与配置对齐；.env.example 补充说明
- or_site_config.sample.json 扩展穿透摄像头与术间绑定示例
- 同步 uv.lock

app/config.py

@@ -41,6 +41,7 @@ class _VideoGroup(_SettingsGroup):
         "video_default_backend",
         "video_camera_backend_overrides_json",
         "video_rtsp_url_template",
+        "video_open_timeout_sec",
         "or_site_config_json_file",
     )
 
@@ -142,6 +143,13 @@ class Settings(BaseSettings):
     video_default_backend: Literal["rtsp", "hikvision_sdk", "auto"] = "rtsp"
     video_camera_backend_overrides_json: str = ""
     video_rtsp_url_template: str = ""
+    #: 单路 RTSP 首次打开超时（秒）；术间「全部摄像头就绪」等待为该值 + 5s。穿透/公网链路可调大。
+    video_open_timeout_sec: float = Field(
+        default=45.0,
+        ge=5.0,
+        le=900.0,
+        validation_alias=AliasChoices("VIDEO_OPEN_TIMEOUT_SEC", "video_open_timeout_sec"),
+    )
     #: 手术室站点配置（UTF-8 JSON）：须含 video_rtsp_urls 与 voice_or_room_bindings，见 or_site_config.sample.json
     or_site_config_json_file: str = ""