Add new functionality for image rectification and depth metadata handling

- Implemented a preview tool for rectifying images with interactive aspect controls in `preview.py`.
- Added tests for depth metadata loading to ensure consistent schema usage in `test_depth_metadata.py`.
- Developed comprehensive tests for cutout calibration processes in `test_cutout_calibration.py`, including stability checks and depth calibration.
- Created tests for frame compositing operations in `test_frame_compositing.py`, ensuring correct handling of depth and transparency.
- Introduced material slot inheritance functionality in `material_slots.py` to manage geometry material assignments.
- Built shared shader nodes for material processing in `shader.py`, including roughness and bump mapping setups.

tests/tools/nodes/test_image_layer.py

@@ -50,9 +50,6 @@ def test_alpha_curve_preserves_endpoints_and_suppresses_soft_edges(image_layer):
 
 def test_depth_layer_keeps_foreground_alpha_threshold(image_layer):
     depth = build_image_depth_layer_group()
-    assert "Alpha Fix" not in {
-        item.name for item in depth.interface.items_tree if item.item_type == "SOCKET"
-    }
     output = next(node for node in depth.nodes if node.type == "GROUP_OUTPUT")
     threshold = output.inputs["Alpha"].links[0].from_node
     assert threshold.operation == "GREATER_THAN"