Refactor geometry generation to standardize Blender object coordinates

- Unified the canonical local frame for generated geometries (Plane, Depth Plane, Relief Plane, Cutout, Depth Cutout) to align with Blender's object coordinate system, setting X as horizontal, Z as up, and +Y as depth.
- Removed the `Depth Axis` parameter from `O Image Cutout` and `O Image Depth Cutout`, simplifying the geometry generation process.
- Updated the depth direction defaults to use +Y instead of -Z for `O Image Relief Plane` and Depth Symmetry.
- Adjusted the geometry nodes to ensure thickness, projection, and shell displacements operate along the Y-axis.
- Implemented new capabilities for handling object space normals to align with the new canonical frame.
- Enhanced the Depth Symmetry functionality to mirror across the canonical Y-axis and perform a final rotation to maintain the correct orientation.
- Added tests to validate the new coordinate system and ensure compatibility with existing assets.

tests/support/planes.py

@@ -25,7 +25,7 @@ def create_surface(plane_type):
     builder = build_image_depth_plane_group if plane_type == "DEPTH" else build_image_relief_plane_group
     group = builder(plane)
     mesh = bpy.data.meshes.new("Rectangle")
-    mesh.from_pydata([(-2, -1, 0), (2, -1, 0), (2, 1, 0), (-2, 1, 0)], [], [(0, 1, 2, 3)])
+    mesh.from_pydata([(-2, 0, -1), (2, 0, -1), (2, 0, 1), (-2, 0, 1)], [], [(0, 1, 2, 3)])
     material = bpy.data.materials.new("Image")
     mesh.materials.append(material)
     obj = bpy.data.objects.new("Surface", mesh)