Walkable/enclosed/refined gates defined; JSONL trace joins request, worker start, build/apply and discards. Coarse-first + dynamic near reserve behind voxel.StreamingCoarseFirst / voxel.StreamingDynamicNearReserve (default 0 = S4 order): matched runs showed no walkability or full-view win and slower LOD0/1 refinement. Instruments settled: 3.1 s standalone reproduced (16.7 s was another generation route); black early captures were clear-only frames. Hashes equal S4; Core-off, M2, SurfaceWorld/FloatingIslands BuildHost pass. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ