feat: Implement depth cutout symmetry and associated functionalities

- Introduced a new proposal for depth cutout symmetry, allowing for the reuse of depth replacement and geometry operations.
- Added requirements for maintaining default thickness values for cutout nodes and ensuring proper initialization during object creation.
- Enhanced symmetry node to handle existing geometry, including alignment, mirroring, and boundary filling.
- Implemented fill smoothing to control the geometry of generated walls while preserving original surfaces.
- Created tests to validate the functionality of the new symmetry features against baseline geometry.
- Updated existing assets and node groups to support the new symmetry capabilities without introducing additional dependencies.

tests/tools/nodes/test_cutout_boundary.py

@@ -83,7 +83,7 @@ def test_split_profile_tapers_within_boundary_band(resolution, aspect):
 
 @pytest.mark.parametrize("mode", [0, 1])
 @pytest.mark.parametrize("reference", [0, 2])
-def test_normal_blend_converges_to_raw_and_reaches_full_smoothing(mode, reference):
+def test_normal_blend_weights_balloon_and_keeps_full_shell_smoothing(mode, reference):
     obj, set_value = surface(resolution=2)
     group = obj.modifiers[0].node_group
     # The production interface renames the Shell thickness socket after building.
@@ -117,6 +117,9 @@ def test_normal_blend_converges_to_raw_and_reaches_full_smoothing(mode, referenc
             results.append(np.array(mesh.attributes["normal_result"].data[0].vector[:]))
         finally:
             ev.to_mesh_clear()
-    np.testing.assert_array_equal(results[0], [0,0,1])
     np.testing.assert_array_equal(results[-1], [1,0,0])
-    assert np.linalg.norm(results[1]-results[0]) < np.linalg.norm(results[2]-results[0]) < .001
+    if mode:
+        np.testing.assert_array_equal(results, [[1,0,0]] * len(results))
+    else:
+        np.testing.assert_array_equal(results[0], [0,0,1])
+        assert np.linalg.norm(results[1]-results[0]) < np.linalg.norm(results[2]-results[0]) < .001