Conservative route slabs with an outside sentinel, tight expanded segment bounds; DensityGrid exact fallbacks
479k -> 0 per run. Near-ready 2-14% faster than L119, still +4.7..+10.2% vs L109; whole view within -0.5..+8%.
Same look (floor offset 7.884 mm, captures checked), seam audit bit-identical, fast tier + walk audits,
Clang/GCC W1/W8/W12 determinism green. BVH and 25 cm tolerance trials rejected. Not for merge yet.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1