Refactor depth surface handling and unify depth sampling rules

- Removed the `always_vertex` parameter from `build_surface_camera` to streamline depth sampling for cutouts and ensure consistent behavior across depth plane and panorama.
- Updated depth sampling logic to ensure that all free boundary points, including the original frame of the depth plane, use neighboring face depth instead of their own texture sampling.
- Adjusted the depth mask deletion process to operate on faces rather than points, eliminating the need for additional cleanup of dangling edges.
- Ensured that the cutout rules are consistently applied across all relevant nodes, removing exceptions and simplifying the logic.
- Updated tests to verify the new behavior, ensuring that cutout points follow the depth of adjacent faces and that the original frame maintains its depth sampling.
- Refactored geometry handling in multiple depth-related nodes to improve clarity and maintainability.

tools/nodes/common/boundary_smoothing.py

@@ -2,7 +2,7 @@
 
 from .nodes import evaluate_field, group_input
 from .depth_surface import _math
-from .smoothing import edge_boundary_field, expand_smooth
+from .smoothing import edge_boundary_field, pinned_smooth
 
 
 def boundary_influence(group, protected=False, *, boundary=None):
@@ -92,9 +92,10 @@ 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):
-    """Move boundary vertices toward the smoothed position through split and outline influence."""
+    """Move boundary vertices toward the pinned 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, "Boundary Smooth", influence)
+    iterations = group_input(group.nodes, {"Boundary Smooth"}).outputs["Boundary Smooth"]
+    return pinned_smooth(group, geometry, iterations, influence)