Add depth surface processing and layout tools

- Implemented `cutout_depth_surface.py` for face separation and connected thickness calculations for depth surface assets.
- Created `cutout_depth_surface_layout.py` to arrange nodes for staggered calculation branches in depth surface processing.
- Authored `geometry_layouts.py` to define layouts for various geometry assets, including image cutouts and depth planes.
- Introduced `node_layout.py` for shared presentation rules, facilitating node arrangement and validation in geometry-node layouts.

tests/test_node_assets.py

@@ -1,4 +1,5 @@
 import unittest
+import sys
 from pathlib import Path
 
 
@@ -7,6 +8,26 @@ SOURCE_ROOT = PROJECT_ROOT / "src" / "anyimage"
 
 
 class NodeAssetsTest(unittest.TestCase):
+    def test_geometry_assets_have_readable_local_layouts(self):
+        import bpy
+
+        sys.path.insert(0, str(PROJECT_ROOT / "tools" / "node_assets"))
+        from node_layout import validate_node_layout
+
+        bpy.ops.wm.read_factory_settings(use_empty=True)
+        with bpy.data.libraries.load(
+            str(SOURCE_ROOT / "assets" / "O_AnyImage.blend")
+        ) as (source, target):
+            target.node_groups = list(source.node_groups)
+        groups = [
+            group
+            for group in target.node_groups
+            if group.bl_idname == "GeometryNodeTree"
+        ]
+        self.assertEqual(len(groups), 7)
+        for group in groups:
+            validate_node_layout(group)
+
     def test_production_code_does_not_create_node_groups(self):
         offenders = []
         for path in SOURCE_ROOT.rglob("*.py"):
@@ -15,9 +36,9 @@ class NodeAssetsTest(unittest.TestCase):
         self.assertEqual(offenders, [])
 
     def test_runtime_node_group_entries_load_assets(self):
-        material_source = (
-            SOURCE_ROOT / "common" / "material.py"
-        ).read_text(encoding="utf-8")
+        material_source = (SOURCE_ROOT / "common" / "material.py").read_text(
+            encoding="utf-8"
+        )
         mesh_plane_source = (
             SOURCE_ROOT / "operators" / "convert_to_plane" / "mesh_plane.py"
         ).read_text(encoding="utf-8")