Add comprehensive tests for image processing and mask functionalities

- Introduced tests for color image handling, ensuring source preservation and premultiplied alpha usage.
- Implemented tests for brush stroke operations, validating segment boundaries and brush anti-aliasing.
- Added tests for frame anti-aliasing, confirming correct rendering behavior with various alpha values and depth settings.
- Created tests for frame projection, ensuring accurate overlap calculations and half-plane clipping.
- Developed tests for image premultiplied retention, verifying behavior during loading and packing processes.
- Added undo functionality tests for mask operations, ensuring single transaction behavior during edits.

src/anyimage/operators/convert_to_plane/object.py

@@ -4,6 +4,7 @@ import bpy
 
 from ...common.image import (
     color_data_name,
+    configure_color_alpha,
     image_empty_bounds,
     image_pixels,
     load_color_result_image,
@@ -42,6 +43,7 @@ def create_color_image(source_object):
         image.pixels.foreach_set(pixels)
         image.update()
     image.name = color_data_name(source_object)
+    configure_color_alpha(image)
     return image