CellView convex polygon edges → clip-space planes (nx,ny,0,d) for gl_ClipDistance,
≤8 with collinear-edge merge. Multi-polygon or >8-edge regions degrade to the union
AABB scissor (over-include, never hide); empty regions are distinct (draw nothing).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
