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/preferences.py

@@ -1,9 +1,9 @@
-import shutil
-import sys
 from pathlib import Path
 
 import bpy
 
+from .runtime import device_enum_items
+
 
 class SnapFormPreferences(bpy.types.AddonPreferences):
     bl_idname = __package__
@@ -17,31 +17,14 @@ class SnapFormPreferences(bpy.types.AddonPreferences):
         subtype="DIR_PATH",
         default=str(Path.home() / ".snapform"),
     )
-    uv_executable: bpy.props.StringProperty(
-        name="uv Executable",
+    device: bpy.props.EnumProperty(
+        name="Device",
         description=(
-            "Path to uv; leave empty to auto-download a standalone uv "
-            "when it is missing"
+            "Inference device used by production tasks; only devices supported "
+            "on this machine are listed"
         ),
-        subtype="FILE_PATH",
-        default=shutil.which("uv") or "",
-    )
-    torch_backend: bpy.props.EnumProperty(
-        name="Torch Backend",
-        description="PyTorch build installed into the isolated Runtime",
-        items=(
-            ("CU128", "CUDA 12.8", "NVIDIA CUDA 12.8 PyTorch wheels"),
-            ("CPU", "CPU", "CPU-only PyTorch wheels"),
-        ),
-        default="CPU" if sys.platform == "darwin" else "CU128",
-    )
-    pypi_index_url: bpy.props.StringProperty(
-        name="PyPI Index",
-        description=(
-            "Package index for the isolated Runtime; leave empty to auto-detect "
-            "with mirror fallback. Example: https://pypi.tuna.tsinghua.edu.cn/simple"
-        ),
-        default="",
+        items=device_enum_items,
+        default=0,
     )
 
     def draw(self, _context):
@@ -50,9 +33,7 @@ class SnapFormPreferences(bpy.types.AddonPreferences):
 
         layout = self.layout
         layout.prop(self, "storage_root")
-        layout.prop(self, "uv_executable")
-        layout.prop(self, "torch_backend")
-        layout.prop(self, "pypi_index_url")
+        layout.prop(self, "device")
         layout.separator()
         layout.label(text=f"Runtime: {runtime_directory()}")
         if runtime_ready():