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.

tests/tools/nodes/test_image_layer.py

@@ -13,8 +13,8 @@ def test_alpha_curve_preserves_endpoints_and_suppresses_soft_edges(image_layer):
         if item.item_type == "SOCKET" and item.in_out == "INPUT"
     }
     assert list(inputs) == [
-        "Color", "Alpha", "Normal", "Bump Scale", "Alpha Fix",
-        "Normal Scale", "Object Space",
+        "Color", "Alpha", "Normal", "Normal Scale", "Bump Scale",
+        "Alpha Fix", "Object Space",
     ]
     strength = inputs["Alpha Fix"]
     output = next(node for node in image_layer.nodes if node.type == "GROUP_OUTPUT")