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/properties.py

@@ -216,17 +216,17 @@ def upscale_model_label(model_key):
     return model.label if model is not None else model_key
 
 
-def refine_region_property():
+def refine_selection_property():
     return bpy.props.BoolProperty(
-        name="Fit to Foreground",
-        description="Use BEN2 to fit the gesture mask to foreground content",
+        name="Refine Selection",
+        description="Use BEN2 to refine the selection to foreground content",
         default=False,
     )
 
 
 def cutout_generate_normal_property():
     return bpy.props.BoolProperty(
-        name="Generate Normal Map",
+        name="Normal Map",
         description=(
             "Generate a MoGe-2 normal texture; Depth Surface uses Object Space "
             "and other shapes use Tangent Space"
@@ -235,25 +235,26 @@ def cutout_generate_normal_property():
     )
 
 
-def cutout_point_spacing_property():
-    return bpy.props.IntProperty(
-        name="Mesh Sampling Spacing",
-        description=(
-            "Source image pixels between neighboring mesh points; smaller values "
-            "create denser geometry"
+def cutout_mesh_detail_property():
+    return bpy.props.EnumProperty(
+        name="Mesh Detail",
+        description="Mesh sampling density",
+        items=(
+            ("LOW", "Low", "32 source image pixels between neighboring mesh points"),
+            ("MEDIUM", "Medium", "16 source image pixels between neighboring mesh points"),
+            ("HIGH", "High", "8 source image pixels between neighboring mesh points"),
+            ("ULTRA", "Ultra", "4 source image pixels between neighboring mesh points"),
         ),
-        default=32,
-        min=4,
-        max=32,
+        default="LOW",
     )
 
 
 class AnyImageSettings(bpy.types.PropertyGroup):
-    cutout_point_spacing: cutout_point_spacing_property()
+    cutout_mesh_detail: cutout_mesh_detail_property()
     cutout_generate_normal: cutout_generate_normal_property()
-    cutout_refine_region: refine_region_property()
-    image_box_refine_region: refine_region_property()
-    image_lasso_refine_region: refine_region_property()
+    cutout_refine_selection: refine_selection_property()
+    image_box_refine_selection: refine_selection_property()
+    image_lasso_refine_selection: refine_selection_property()
     input_path: bpy.props.StringProperty(
         name="Image or Video",
         description="A single image or video file used for reconstruction",