passages: exact relief skip + per-tile BVH node masks (L82); FI/TN LOD0-2 -12%

- Wall relief noise is skipped when its hard-bounded contribution cannot change the final max;
  mouth surface/tread noise only on paths that use it.
- Exact active BVH-node masks cached per tile/passage/segment range; no per-sample lower_bound.
- Full-view audit imports the exported Core plan (not the stale 26-point root route): 21,425/21,425
  walkability samples pass.
Cold (L80 protocol, medians) LOD0-2: SW 1.16->1.11, FI 2.86->2.51, TN 2.88->2.54, VS 1.23->1.22 s.
Passage share FI 64.6->58.7%, TN 65.4->58.4%. Hashes identical (v214). TN "slowdown" from L81
not reproduced (5 pairs, 3.08 -> 2.75 s). Fast tier PASS; Linux UE host builds.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Standalone/Source/StreamBenchmarkHeadless.cpp

@@ -2242,7 +2242,7 @@ int main(int argc,char** argv)
         std::chrono::duration<double,std::milli>(Clock::now()-planStart).count());
 
     auto snapshot=VoxelForgeCore::MakeStandaloneSnapshotFromParsedJson(ownerJsonRoot,seed,
-        options.ClipRadius,options.MaxClipLevel,false,false,error);
+        options.ClipRadius,options.MaxClipLevel,false,false,error,useExportedCorePlan);
     if(!snapshot)
     {std::fprintf(stderr,"Shape interval build failed: %s\n",error.c_str());return 2;}