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`.

tests/test_image_depth.py

@@ -23,25 +23,66 @@ def load_image_depth():
     )
     fake_bpy.types = SimpleNamespace(Menu=object, Operator=object)
     fake_bpy.path = SimpleNamespace(abspath=lambda path: path)
-    with patch.dict(sys.modules, {"bpy": fake_bpy}):
-        specification = importlib.util.spec_from_file_location(
-            "snapform_image_depth_test",
-            PROJECT_ROOT
-            / "src"
-            / "snapform"
-            / "blender"
-            / "depth_plane.py",
-        )
-        module = importlib.util.module_from_spec(specification)
-        specification.loader.exec_module(module)
-    return module
+    fake_bpy.context = SimpleNamespace(scene=None)
 
+    module_paths = (
+        (
+            "snapform.operators.image",
+            PROJECT_ROOT / "src" / "snapform" / "operators" / "image.py",
+        ),
+        (
+            "snapform.operators.material",
+            PROJECT_ROOT / "src" / "snapform" / "operators" / "material.py",
+        ),
+        (
+            "snapform.operators.depth_plane.data",
+            PROJECT_ROOT / "src" / "snapform" / "operators" / "depth_plane" / "data.py",
+        ),
+        (
+            "snapform.operators.depth_plane.build",
+            PROJECT_ROOT / "src" / "snapform" / "operators" / "depth_plane" / "build.py",
+        ),
+    )
+    packages = {
+        name: ModuleType(name)
+        for name in (
+            "snapform",
+            "snapform.operators",
+            "snapform.operators.depth_plane",
+        )
+    }
+    for package in packages.values():
+        package.__path__ = []
+
+    loaded = []
+    with patch.dict(sys.modules, {"bpy": fake_bpy, **packages}):
+        for module_name, module_path in module_paths:
+            specification = importlib.util.spec_from_file_location(
+                module_name,
+                module_path,
+            )
+            module = importlib.util.module_from_spec(specification)
+            sys.modules[module_name] = module
+            specification.loader.exec_module(module)
+            loaded.append(module)
+
+    namespace = SimpleNamespace()
+    for module in loaded:
+        for name, value in vars(module).items():
+            if not name.startswith("__"):
+                setattr(namespace, name, value)
+    return namespace
 
 class ImageDepthTest(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
         cls.image_depth = load_image_depth()
 
+    def test_material_asset_path_survives_package_split(self):
+        self.assertEqual(
+            self.image_depth.node_asset_path(),
+            PROJECT_ROOT / "src" / "snapform" / "assets" / "O_SnapForm.blend",
+        )
     def test_material_color_space_matches_scene_view_transform(self):
         mappings = {
             "ACES 1.3": "ACES 1.3 sRGB",
@@ -651,7 +692,7 @@ class ImageDepthTest(unittest.TestCase):
             "img.001.depth",
         )
 
-    def test_moge_map_names_use_source_image_name(self):
+    def test_moge_normal_name_uses_source_image_name(self):
         source_object = SimpleNamespace(
             name="obj_img",
             data=SimpleNamespace(name="img.png"),
@@ -661,10 +702,6 @@ class ImageDepthTest(unittest.TestCase):
             self.image_depth.normal_data_name(source_object),
             "img.normal",
         )
-        self.assertEqual(
-            self.image_depth.mask_data_name(source_object),
-            "img.mask",
-        )
 
     def test_copy_depth_image_renames_still_source(self):
         class FakeImage: