Add cutout shell and volume node assets for depth volume processing

- Implemented `cutout_shell.py` to build front normals and shell positions for balloon geometry.
- Created `cutout_volume.py` to establish smooth center fields and manage balloon surface attributes.
- Introduced `pisa_sr_export.py` for exporting PiSA-SR components with dependencies and asset finalization.

src/anyimage/operators/cutout_tool/geometry.py

@@ -1238,6 +1238,35 @@ class BaseShape:
     balloon: object
 
 
+def refine_balloon_triangles(points, faces, boundary):
+    """Add interior samples to boundary ears and interior boundary chords."""
+    from collections import Counter
+    import numpy as np
+
+    edges = Counter(tuple(sorted((face[i], face[(i + 1) % 3]))) for face in faces for i in range(3))
+    values, midpoints = list(points), {}
+    for edge, count in edges.items():
+        if count == 2 and all(boundary[index] for index in edge):
+            midpoints[edge] = len(values)
+            values.append(points[list(edge)].mean(axis=0))
+    refined = []
+    for face in faces:
+        ring = []
+        for index, vertex in enumerate(face):
+            ring.append(vertex)
+            midpoint = midpoints.get(tuple(sorted((vertex, face[(index + 1) % 3]))))
+            if midpoint is not None:
+                ring.append(midpoint)
+        if len(ring) == 3 and not all(boundary[vertex] for vertex in face):
+            refined.append(tuple(face))
+            continue
+        center = len(values)
+        values.append(points[list(face)].mean(axis=0))
+        refined.extend((center, ring[i], ring[(i + 1) % len(ring)]) for i in range(len(ring)))
+    points = np.asarray(values)
+    return points, refined, boundary_vertices_from_faces(len(points), refined)
+
+
 def cutout_domain(
     selection_contours,
     bounds,
@@ -1276,6 +1305,17 @@ def cutout_domain(
             (start, end, faces.tolist(), pixel_to_planar(contour))
             for start, end, faces, contour in pixel_components
         ]
+    refined_points, refined_faces, refined_components = [], [], []
+    offset = 0
+    for start, end, component_faces, contour in components:
+        points, faces, _ = refine_balloon_triangles(planar[start:end], component_faces, boundary[start:end])
+        refined_points.append(points)
+        refined_faces.extend(tuple(offset + index for index in face) for face in faces)
+        refined_components.append((offset, offset + len(points), faces, contour))
+        offset += len(points)
+    planar = np.concatenate(refined_points)
+    planar_faces, components = refined_faces, refined_components
+    boundary = boundary_vertices_from_faces(len(planar), planar_faces)
     profile = balloon_profile(
         balloon_algorithm, planar, planar_faces, boundary, components
     )