Enhance device management and model handling in SnapForm

- Updated frame extraction logic to allow for single frame extraction.
- Integrated model readiness checks for BEN2 and DA3 models in relevant operators.
- Added directory name attribute to model specifications for better organization.
- Improved device selection logic for production and debug tasks.
- Refactored preferences to expose device settings and ensure they reflect available hardware.
- Enhanced runtime device detection and management, including support for CUDA and MPS.
- Updated tests to cover new device management features and model directory handling.
- Removed deprecated download model tests to streamline codebase.

src/snapform/operators.py

@@ -337,6 +337,7 @@ class RunJob(bpy.types.Operator):
                     paths["result"],
                     BEN2_MODEL.key,
                     start_frame=start_frame,
+                    device=self._task_device(settings),
                 ),
                 paths,
             )
@@ -398,10 +399,21 @@ class RunJob(bpy.types.Operator):
                     self.job_type == IMAGE_DEPTH_JOB
                     and remove_background
                 ),
+                device=self._task_device(settings),
             ),
             paths,
         )
 
+    def _task_device(self, settings):
+        """Debug panels use the scene device; production tasks use Preferences."""
+        if self.job_type in {
+            IMAGE_DEPTH_JOB,
+            IMAGE_BACKGROUND_JOB,
+            ORIGINAL_BACKGROUND_JOB,
+        }:
+            return runtime.production_device()
+        return settings.device
+
     def _require_online_access(self):
         if not bpy.app.online_access:
             raise RuntimeError(