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/groups/image_depth_plane.py

@@ -2,7 +2,7 @@
 
 import bpy
 
-from ..common.validity import delete_invalid_points
+from ..common.validity import delete_invalid_faces
 
 from ..common.nodes import group_input as _group_input, interface_socket as _interface_socket
 from ..common.nodes import prepare_node_group, float_input, evaluate_field
@@ -107,7 +107,7 @@ def build_image_depth_plane_group(image_plane_group):
                    _math(group, "MINIMUM", _math(group, "SUBTRACT", 1, u), _math(group, "SUBTRACT", 1, v)))
     original_boundary = evaluate_field(group, _math(group, "LESS_THAN", margin, 1e-6), "BOOLEAN", "POINT")
     protected = plane.outputs["Geometry"]
-    culled = delete_invalid_points(group, protected, invalid.outputs["Result"])
+    culled = delete_invalid_faces(group, protected, invalid.outputs["Result"])
     cull_controls = _group_input(nodes, {"Depth Mask"})
     cull = nodes.new("GeometryNodeSwitch")
     cull.input_type = "GEOMETRY"