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.

docs/internals/operators/rectify.md

@@ -1,6 +1,6 @@
 # Rectify 透视校正
 
-`operators/rectify_tool.py` 定义 `RectifyImagePerspective` 与 `RectifyTool`，将图片内的四角区域校正为矩形。
+`operators/rectify_tool/operators.py` 定义 `RectifyImagePerspective` 与 `RectifyTool`，将图片内的四角区域校正为矩形。`geometry.py` 负责四角验证与像素校正，`preview.py` 负责预览图、Overlay 和宽高比控制，`__init__.py` 导出类型及注册清单。
 
 ```mermaid
 flowchart TD