Add new node asset scripts for geometry and shader operations

- Implemented `build_mesh_plane.py` to create a geometry node group for mesh planes with customizable parameters.
- Created `build_shadeless.py` for a shader node group that displays color without scene lighting while preserving shadows and reflections.
- Added `validate.py` to validate the integrity of the newly created node groups and their inputs.
- Introduced `validate_cutout.py` to ensure the functionality of cutout node groups and their dependencies.
- Developed `validate_mesh_plane.py` to test the mesh plane creation and its modifier settings.

src/anyimage/server/geometry/__init__.py

@@ -1,35 +1,7 @@
-from .grid_mesh import (
-    compact_mesh,
-    confidence_percentile_map,
-    confidence_percentile_threshold,
-    depth_edge_mask,
-    depth_discontinuity_ratio,
-    edge_culling_stretch_limit,
-    foreground_mesh_mask,
-    mesh_triangle_faces,
-    remove_background_faces,
-    triangle_edge_stretch_values,
-    triangle_edge_stretch_mask,
-)
 from .projection import unproject_camera_depth, unproject_depth_frame
-from .surface import GeometryFrame, SurfaceMesh, build_surface
 
 
 __all__ = (
-    "GeometryFrame",
-    "SurfaceMesh",
-    "build_surface",
-    "compact_mesh",
-    "confidence_percentile_map",
-    "confidence_percentile_threshold",
-    "depth_edge_mask",
-    "depth_discontinuity_ratio",
-    "edge_culling_stretch_limit",
-    "foreground_mesh_mask",
-    "mesh_triangle_faces",
-    "remove_background_faces",
-    "triangle_edge_stretch_values",
-    "triangle_edge_stretch_mask",
     "unproject_camera_depth",
     "unproject_depth_frame",
 )