Prevent configure while processor running

Add a lifecycle lock and guard in DLCLiveProcessor.configure to ensure the processor is stopped before reconfiguration. The method now acquires self._lifecycle_lock and raises a RuntimeError if the processor state is not WorkerState.STOPPED, preventing concurrent/race-condition updates to settings or processor while running.

Author: C-Achard

dlclivegui/services/dlc_processor.py

@@ -181,6 +181,9 @@ def get_model_backend(model_path: str) -> Engine:
         return Engine.from_model_path(model_path)
 
     def configure(self, settings: DLCProcessorSettings, processor: Any | None = None) -> None:
+        with self._lifecycle_lock:
+            if self._state != WorkerState.STOPPED:
+                raise RuntimeError("Cannot configure DLCLiveProcessor while it is running. Please stop it first.")
         self._settings = settings
         self._processor = processor