Add comprehensive tests for image processing nodes and refactor node imports

- Introduced new test files for image layer, image plane, normal scale, object normal rotation, shadeless, and temporary attributes.
- Implemented tests to validate the behavior of alpha curves, depth layers, and normal scales in various rendering engines.
- Refactored import paths for node groups to align with the new directory structure.
- Added checks for temporary attribute lifetimes and ensured proper cleanup without warnings.
- Enhanced CLI commands to require the Blender group and validate the presence of generated node assets before packaging.
- Updated packaging scripts to enforce the existence of necessary assets, preventing build failures.

tests/nodes/test_cutout_boundary.py

@@ -0,0 +1,72 @@
+"""Verify split profile shaping and displacement direction shaping."""
+
+import bpy
+import numpy as np
+import pytest
+
+from tests.support.depth_surface import surface, evaluated
+from tests.nodes.test_boundary_smoothing import diagonal_surface
+
+
+def profile_values(obj):
+    result = obj.evaluated_get(bpy.context.evaluated_depsgraph_get())
+    mesh = result.to_mesh()
+    try:
+        return np.array([v.value for v in mesh.attributes["o_balloon"].data])
+    finally:
+        result.to_mesh_clear()
+
+
+def vertex_uv(obj):
+    result = obj.evaluated_get(bpy.context.evaluated_depsgraph_get())
+    mesh = result.to_mesh()
+    try:
+        uv = np.zeros((len(mesh.vertices), 2))
+        for loop in mesh.loops:
+            uv[loop.vertex_index] = mesh.uv_layers["UVMap"].data[loop.index].uv
+        return uv
+    finally:
+        result.to_mesh_clear()
+
+
+@pytest.mark.parametrize("iterations", [0, 16])
+def test_cleaned_sawtooth_smoothing_preserves_face_orientation(iterations):
+    obj, set_value = diagonal_surface(triangles=True)
+    original, faces = evaluated(obj)
+    set_value("Boundary Smooth", iterations)
+    points, actual = evaluated(obj)
+    assert actual == faces
+    indices = np.array(faces)
+    def normals(p):
+        return np.cross(p[indices[:,1]]-p[indices[:,0]], p[indices[:,2]]-p[indices[:,0]])
+    assert np.all(np.sum(normals(original)*normals(points), axis=1) > 0)
+
+
+def test_split_profile_tapers_within_boundary_band():
+    resolution, aspect = 12, .5
+    obj, set_value = surface(step=6, resolution=resolution)
+    for vertex in obj.data.vertices:
+        vertex.co.x *= aspect
+    image = bpy.data.images["Camera"]
+    pixels = np.array(image.pixels[:], np.float32).reshape(32, 64, 4)
+    pixels[..., 0] *= aspect
+    image.pixels.foreach_set(pixels.ravel())
+    image.update()
+    obj.data.attributes.new("o_balloon", "FLOAT", "POINT").data.foreach_set(
+        "value", np.full(len(obj.data.vertices), .3, dtype=np.float32))
+    set_value("Depth Scale", 1)
+    np.testing.assert_allclose(profile_values(obj), .3)
+    set_value("Depth Split", .1)
+    values = profile_values(obj)
+    uv = vertex_uv(obj)
+    # The depth step sits at u=0.5, so only that column is tapered.
+    cut = (np.abs(uv[:, 0] - .5) < 1e-4) & (uv[:, 1] > 1e-3) & (uv[:, 1] < 1 - 1e-3)
+    assert cut.any()
+    np.testing.assert_array_equal(values[cut], 0)
+    untouched = (np.abs(uv[:, 0] - .25) < 1e-3) | (np.abs(uv[:, 0] - .75) < 1e-3)
+    assert untouched.any()
+    np.testing.assert_allclose(values[untouched], .3)
+    assert np.isfinite(values).all()
+    assert values.max() == pytest.approx(.3)
+    set_value("Depth Split", 0)
+    np.testing.assert_allclose(profile_values(obj), .3)