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/validity.py

@@ -1,21 +1,10 @@
-"""Remove invalid vertices and the wire edges left by point deletion."""
+"""Delete the faces the depth mask excludes."""
 
 
-def delete_invalid_points(group, geometry, invalid):
+def delete_invalid_faces(group, geometry, invalid):
     nodes, links = group.nodes, group.links
     delete = nodes.new("GeometryNodeDeleteGeometry")
-    delete.domain, delete.mode = "POINT", "ALL"
+    delete.domain, delete.mode = "FACE", "ALL"
     links.new(geometry, delete.inputs["Geometry"])
     links.new(invalid, delete.inputs["Selection"])
-    neighbors = nodes.new("GeometryNodeInputMeshEdgeNeighbors")
-    wire = nodes.new("FunctionNodeCompare")
-    wire.data_type, wire.operation = "INT", "EQUAL"
-    a = next(socket for socket in wire.inputs if socket.identifier == "A_INT")
-    b = next(socket for socket in wire.inputs if socket.identifier == "B_INT")
-    b.default_value = 0
-    links.new(neighbors.outputs["Face Count"], a)
-    cleanup = nodes.new("GeometryNodeDeleteGeometry")
-    cleanup.domain, cleanup.mode = "EDGE", "ALL"
-    links.new(delete.outputs["Geometry"], cleanup.inputs["Geometry"])
-    links.new(wire.outputs["Result"], cleanup.inputs["Selection"])
-    return cleanup.outputs["Geometry"]
+    return delete.outputs["Geometry"]