feat: Implement weight cutout boundary smoothing for image depth cutout

- Added a new proposal for boundary smoothing in the weight cutout process, differentiating between Split edges and Outline smoothing requirements.
- Introduced a new capability `cutout-boundary-smoothing` to control smoothing strength and default values.
- Updated specifications to define the behavior of boundary-specific smoothing strength and default settings.
- Created tasks to verify the implementation of boundary behavior and asset updates.
- Developed comprehensive tests for depth symmetry and normal scaling to ensure expected behavior and performance.
- Introduced new attributes for normal mapping to facilitate persistent face attributes sharing between depth symmetry and image materials.
- Built a new node group for O Image Depth Symmetry, integrating the new smoothing capabilities and ensuring compatibility with existing workflows.

tools/nodes/arrangement/arrange.py

@@ -1,4 +1,4 @@
-"""Materialize the joint calculation and connection plan in geometry node trees."""
+"""Materialize the joint calculation and connection plan in node trees."""
 
 from .branches import calculation_blocks
 from .dimensions import estimate_node_dimensions, visible_socket