Refactor depth node groups and simplify options

- Removed `Smooth Weight` input from `O Image Depth Plane`, `O Image Depth Cutout`, and `O Image Depth Panorama` to streamline the interface and maintain consistent boundary smoothing behavior.
- Adjusted the `Reference Depth` input to appear last in the options panel for better organization, reflecting its role as a calibration value.
- Consolidated the `expand_smooth()` function to only accept necessary parameters, eliminating unused branches related to `Smooth Weight` and `pin_sharp`.
- Updated related tests and node assets to ensure functionality remains intact and consistent with the new structure.
- Introduced new specifications to document the changes and ensure compliance with the updated requirements.

tools/nodes/common/boundary_smoothing.py

@@ -92,12 +92,9 @@ def cut_boundary_influence(group, split_boundary, protected=False, *, outline_sc
 
 
 def smooth_cut_boundary(group, geometry, split_boundary=False, *, protected=False, outline_scale=0.1, boundary=None):
-    """Blend O Smooth through split and outline masks with configurable weights."""
+    """Move boundary vertices toward the smoothed position through split and outline influence."""
     influence = cut_boundary_influence(
         group, split_boundary, protected, outline_scale=outline_scale, boundary=boundary,
     )
     # The support band depends on topology, which stays unchanged in the loop.
-    return expand_smooth(
-        group, geometry, iterations_name="Boundary Smooth", weight_name="Smooth Weight",
-        influence=influence, pin_sharp=False,
-    )
+    return expand_smooth(group, geometry, "Boundary Smooth", influence)