Include camera ID in unknown camera label

Update the fallback camera display name to include the camera ID (`Unknown camera [<id>]`) instead of a generic `Unknown camera`, making unidentified cameras easier to distinguish in the UI.

Author: C-Achard

dlclivegui/gui/main_window.py

@@ -1546,7 +1546,7 @@ def _label_for_cam_id(self, cam_id: str) -> str:
         if display_id:
             return display_id
 
-        return "Unknown camera"
+        return f"Unknown camera [{cam_id}]"
 
     def _refresh_dlc_camera_list_running(self) -> None:
         """Populate inference camera dropdown from currently running cameras.