Add model catalog with specifications for DA3 and MoGe-2 models

- Introduced ModelSpec dataclass to define model attributes.
- Added multiple models including DA3 Small, Base, Giant 1.1, Nested Giant Large 1.1, and MoGe-2 variants.
- Implemented functions to retrieve model details and metadata.
- Included BEN2 model specifications for background removal.

src/snapform/preferences.py

@@ -43,7 +43,7 @@ class SnapFormPreferences(bpy.types.AddonPreferences):
                 icon="IMPORT",
             )
         layout.separator()
-        operator = layout.operator(
+        layout.operator(
             "snapform.open_server_log",
             text="Open Server Log",
             icon="TEXT",