passages: tunnels own their floor - flat-bottomed tube + solid shell (L109, v217) - pending visual review

Owner design: flat world-horizontal floor (0.50 m corner blend), 0.75 m solid shell written only
where the host field is air (interiors union first and beat every shell), 5 m cubic mouth ramps.
Removed route support restoration, deferred support, support columns, mouth-support restoration
and their capsule checks (-5,129 / +1,641 lines). Near-ready @W12: FI 1.39 -> 0.86, TN 1.29 ->
0.90, VS 0.85 -> 0.74, SW 0.70 -> 0.76 s (more shell/skirt surface). All walk audits pass;
Clang/GCC W1/W8/W12 deterministic; fast tier PASS; Linux UE builds; 6 UE arrival traces pass.
OPEN ISSUE: open-air shell (e.g. passage 0-1, 1037-1489 m route span) shows a regular stepped
banding pattern - not merged into assembler/world until fixed/approved.

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

Standalone/Source/StreamingWorld.h

@@ -1580,37 +1580,17 @@ private:
             static_cast<unsigned long long>(D.islandSharedCacheConflictReplacements),
             static_cast<double>(D.islandSharedCacheLockWaitNanoseconds)/1000.0);
         if(D.passageComposerProfiled)
-            std::printf("[PassageComposerTile] key=(%d,%d,%d,lod%d) worker_ms=%.3f samples=%llu native_field_calls=%llu features=%llu route_candidates=%llu mouth_candidates=%llu boundary_band_queries=%llu queries=%llu passage_iterations=%llu tile_bound_checks=%llu tile_bound_rejects=%llu tile_bound_skipped_iterations=%llu upper_mouth_checks=%llu column_candidates=%llu column_distance_calls=%llu negative_bounds=%llu negative_rejects=%llu positive_bounds=%llu positive_rejects=%llu carve_segment_visits=%llu smooth_carve_joins=%llu support_segment_visits=%llu smooth_support_joins=%llu support_capsule_checks=%llu later_bore_checks=%llu other_capsule_checks=%llu mouth_support_calls=%llu mouth_route_segment_checks=%llu relief_field_calls=%llu smoothstep_evaluations=%llu sweep_segments=%llu sweep_pairs=%llu sweep_outside_pairs=%llu sweep_min_updates=%llu sweep_base_samples=%llu sweep_detail_samples=%llu sweep_grid_samples=%llu sweep_no_influence_samples=%llu sweep_lookups=%llu sweep_cache_hits=%llu sweep_base_hits=%llu sweep_outside_hits=%llu sweep_missing=%llu\n",
+            std::printf("[PassageComposerTile] key=(%d,%d,%d,lod%d) worker_ms=%.3f samples=%llu native_field_calls=%llu features=%llu route_candidates=%llu boundary_band_queries=%llu queries=%llu passage_iterations=%llu carve_segment_visits=%llu relief_field_calls=%llu sweep_segments=%llu sweep_pairs=%llu sweep_outside_pairs=%llu sweep_min_updates=%llu sweep_base_samples=%llu sweep_detail_samples=%llu sweep_grid_samples=%llu sweep_no_influence_samples=%llu sweep_lookups=%llu sweep_cache_hits=%llu sweep_base_hits=%llu sweep_outside_hits=%llu sweep_missing=%llu\n",
                 Event.Key.Coord.X,Event.Key.Coord.Y,Event.Key.Coord.Z,Event.Key.Level,
                 Event.WorkerMilliseconds,static_cast<unsigned long long>(Event.DensitySamples),
                 static_cast<unsigned long long>(D.fieldCalls),
                 static_cast<unsigned long long>(D.passageTileFeatureCount),
                 static_cast<unsigned long long>(D.passageTileRouteSegmentCandidates),
-                static_cast<unsigned long long>(D.passageTileMouthSegmentCandidates),
                 static_cast<unsigned long long>(D.resolvedBoundaryBandQueries),
                 static_cast<unsigned long long>(D.passageComposerQueries),
                 static_cast<unsigned long long>(D.passageIterations),
-                static_cast<unsigned long long>(D.passageTileBoundChecks),
-                static_cast<unsigned long long>(D.passageTileBoundRejects),
-                static_cast<unsigned long long>(D.passageTileBoundSkippedIterations),
-                static_cast<unsigned long long>(D.passageUpperMouthFilterChecks),
-                static_cast<unsigned long long>(D.passageColumnCandidates),
-                static_cast<unsigned long long>(D.passageColumnDistanceCalls),
-                static_cast<unsigned long long>(D.passageNegativeBoundChecks),
-                static_cast<unsigned long long>(D.passageNegativeBoundRejects),
-                static_cast<unsigned long long>(D.passagePositiveBoundChecks),
-                static_cast<unsigned long long>(D.passagePositiveBoundRejects),
                 static_cast<unsigned long long>(D.passageCarveSegmentVisits),
-                static_cast<unsigned long long>(D.passageSmoothCarveJoins),
-                static_cast<unsigned long long>(D.passageSupportSegmentVisits),
-                static_cast<unsigned long long>(D.passageSmoothSupportJoins),
-                static_cast<unsigned long long>(D.passageSupportCapsuleChecks),
-                static_cast<unsigned long long>(D.passageLaterBoreChecks),
-                static_cast<unsigned long long>(D.passageOtherCapsuleChecks),
-                static_cast<unsigned long long>(D.passageMouthSupportCalls),
-                static_cast<unsigned long long>(D.passageMouthRouteSegmentChecks),
                 static_cast<unsigned long long>(D.passageReliefFieldCalls),
-                static_cast<unsigned long long>(D.passageSmoothstepEvaluations),
                 static_cast<unsigned long long>(D.passageSweepRouteSegmentCandidates),
                 static_cast<unsigned long long>(D.passageSweepSegmentSamplePairs),
                 static_cast<unsigned long long>(D.passageSweepOutsideInfluencePairs),