Add operators for model downloading and surface generation

- Implemented `DownloadModel` and `DownloadRequiredModels` operators for downloading models.
- Created `ClearModels` operator to clear model resources.
- Added `ConvertToSurface` operator for converting image empties into textured surfaces.
- Introduced `GenerateDa3Surface` and `GenerateMoge2Surface` operators for generating surfaces using DA3 and MoGe-2 models respectively.
- Developed utility functions for handling image mesh data, assigning attributes, and managing geometry nodes.
- Established runtime configuration and post-installation model downloading in `runtime.py`.

tools/validate_moge_surface.py

@@ -13,12 +13,11 @@ sys.path.insert(
     str(next((PROJECT_ROOT / "src" / "snapform" / "wheels").glob("blendjob-*.whl"))),
 )
 
-from snapform.blender.depth_plane import MOGE_SURFACE_MATERIAL_NODE_GROUP_NAME
-from snapform.blender.depth_plane import material_color_space_name
-from snapform.blender.surface import (
-    MOGE_NODE_GROUP_NAME,
-    build_image_mesh,
+from snapform.operators.material import (
+    MOGE_SURFACE_MATERIAL_NODE_GROUP_NAME,
+    material_color_space_name,
 )
+from snapform.operators.surface import MOGE_NODE_GROUP_NAME, build_image_mesh
 from snapform.server.geometry import GeometryFrame, build_surface
 from snapform.server.outputs.surface import write_surface_archive