Self's calls (flat seams stay on the cutter plane, hull vertices survive, hull-side edge flips, cap CDT,
5 deg guard) and ruling weld-owner-local-corners-kept (per-vertex ownership, cutter and crease corners
never merged or moved). Box cut-ins added. Seam off plane 3e-16, crack 0, cap worst angle 0.058 to
5.5 deg; the hull-side worst angle is pinned by near-coincident seam/hull vertex pairs. All corners kept.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
db2c162a79