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.

tests/test_models.py

@@ -54,3 +54,21 @@ class ModelTest(unittest.TestCase):
             ("config.json", "model.safetensors"),
         )
         self.assertNotIn("BEN2_BASE", self.models.MODELS)
+
+    def test_da3_model_directories_share_the_da3_prefix(self):
+        for model_key, model in self.models.MODELS.items():
+            with self.subTest(model_key=model_key):
+                self.assertTrue(
+                    model.directory_name.startswith("da3_"),
+                    model.directory_name,
+                )
+                self.assertEqual(
+                    self.models.model_directory_name(model_key),
+                    model.directory_name,
+                )
+
+    def test_ben2_model_directory_uses_ben2_prefix(self):
+        self.assertEqual(
+            self.models.model_directory_name("BEN2_BASE"),
+            "ben2_base",
+        )