Refactor depth reference handling and cleanup

- Unified reference depth calculation to use a single implementation in common/depth.py.
- Removed server-side reference depth computation and adjusted depth.json to only include image_size and intrinsics.
- Updated depth texture handling to ignore transparent, invalid, and non-positive pixels when calculating reference depth.
- Changed reference depth calculation to use the 95th percentile of valid depth values.
- Adjusted depth direction fitting to return a flat direction when no samples are available.
- Removed cleanup threshold parameters from Cutout and related nodes, simplifying the interface.
- Updated tests to verify new reference depth logic and ensure compatibility with existing functionality.

tests/anyimage/operators/test_conversion_source_images.py

@@ -48,12 +48,13 @@ def run_conversion(source, entry, monkeypatch):
     if entry == "PLANE":
         operators.ConvertToPlane.execute(SimpleNamespace(mesh_detail=0), bpy.context)
     else:
-        metadata = {"image_size": (2, 1), "reference_depth": 1,
+        metadata = {"image_size": (2, 1),
                     "intrinsics": ((2, 0, 1), (0, 2, 0.5), (0, 0, 1))}
         monkeypatch.setattr(conversion, "load_depth_metadata", lambda _: metadata)
         def load_depth(*_):
             image = bpy.data.images.new("Depth", width=2, height=1, float_buffer=True)
             image.colorspace_settings.name = "Non-Color"
+            image.pixels.foreach_set(np.ones(8, dtype=np.float32))
             return image
         monkeypatch.setattr(conversion, "load_depth_result_image", load_depth)
         monkeypatch.setattr(conversion, "load_normal_result_image", load_depth)