wip(L28): passage columns/routes culled per tile (BVH); cost back near L24, bit-identical to L27

GenerateMesh scopes passage queries to the tile's sample bounds with a feature AABB BVH plus
per-passage segment BVHs; L9 proof boxes use a passage-bound BVH. Whole view vs L24: FI ~0%, SW
+3.7% (reviewer interleaved). All hashes equal L27; all passage/route/proof audits pass.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CSFYgsdW8ejZSyiMf4qRSX

CODEMAP.md

@@ -1208,6 +1208,15 @@ The shared evaluator is version 13; FloatingIslands geometry remains version 7 a
 schema V3 is unchanged. See ARCHITECTURE §8.44 and
 [`Standalone/Research/WorldAssemblerM3/Linux26/REPORT.md`](Standalone/Research/WorldAssemblerM3/Linux26/REPORT.md).
 
+### 3.28 Tile-bounded passage evaluation — World Assembler M3 Linux L28
+
+| Symbol | Canonical file | Role |
+|---|---|---|
+| FScopedPassageTileQueries / BuildPassageFeatureTileList / ResolvedPassageIntersectsBox | Standalone/Core/src/ShapeWorldInternal.h; scope entered by GenerateMesh in Standalone/Core/src/VoxelForgeCore.cpp | Builds conservative per-tile route, column and mouth-support candidates from an AABB BVH; long paths use a nearest-segment BVH and L9 box checks use a separate passage-bound BVH. Empty native-only proof indexes fall back conservatively. The density arithmetic and serialized versions stay unchanged. |
+
+See ARCHITECTURE §8.45 and
+[Linux28 report](Standalone/Research/WorldAssemblerM3/Linux28/REPORT.md).
+
 ## 4. The density pipeline (most-edited hot path)
 
 ### 4.1 `GetDensityWithParams` (TunnelNetwork) — VoxelGenerator.cpp:3749