Add tests and implement boundary smoothing and cutout functionality

- Introduced tests for boundary smoothing in `test_boundary_smoothing.py`, verifying that smoothing reduces stair-step artifacts while preserving boundary integrity.
- Added tests for cutout boundary behavior in `test_cutout_boundary.py`, ensuring proper handling of boundary triangles and normal blending.
- Created `test_temporary_attributes.py` to check the cleanup of temporary attributes across depth modifier branches, ensuring no warnings are raised.
- Implemented point culling functionality in `test_validity.py`, confirming that invalid points are removed without affecting adjacent geometry.
- Developed boundary smoothing logic in `boundary_smoothing.py`, allowing for depth smoothing while maintaining edge integrity.
- Added cutout boundary management in `cutout_boundary.py`, including functions for removing boundary triangles and tapering thickness profiles.
- Implemented validity checks in `validity.py` to ensure proper deletion of invalid vertices and associated wire edges.

tools/nodes/arrangement/dimensions.py

@@ -40,7 +40,7 @@ def estimate_node_dimensions(node):
 
     # Conservative reserves include spacing between UI sections.
     controls = RULES["controls"][node.bl_idname]
-    for collection in ("repeat_items", "state_items", "input_items", "main_items", "generation_items", "capture_items", "enum_items"):
+    for collection in ("repeat_items", "state_items", "input_items", "main_items", "generation_items", "enum_items"):
         controls += len(getattr(node, collection, ()))
     if node.bl_idname == "GeometryNodeGroup" and node.node_tree:
         controls += sum(item.item_type == "PANEL" for item in node.node_tree.interface.items_tree)