Add image selection refinement functionality with BEN2 integration

- Implemented viewport.py for handling 3D view projections, gestures, and overlay drawing.
- Created refine_image_selection.py to manage the refinement of gesture masks and output image bounds.
- Added selection module with refine_selection.py to process and crop images based on alpha channel visibility.
- Introduced __init__.py for selection module to expose refine_selection function.

src/anyimage/operators/remove_background.py

@@ -2,7 +2,7 @@ import bpy
 
 from ..properties import BEN2_MODEL_KEY
 from ..runtime import JobOperatorBase
-from ..common.ai_job import (
+from ..common.ai import (
     require_background_input_path,
     invoke_ai_setup_if_needed,
     production_device,
@@ -10,7 +10,7 @@ from ..common.ai_job import (
     require_model,
 )
 
-from ..common.image_data import (
+from ..common.image import (
     cleanup_image_input,
     default_extract_frames,
     is_image_empty,
@@ -70,7 +70,7 @@ class RemoveImageBackground(bpy.types.Operator):
 
 
 def apply_background_response(result, source_object_name):
-    from ..common.image_data import (
+    from ..common.image import (
         load_color_result_image,
         replace_empty_image,
         require_image_empty,