streaming: deeper ready queue + startup apply cap; tile-local mouth-support culling (L72)

- Unreal: ready queue depth 8 -> 16 (cap 4 worker-sets / 64), startup mesh-apply cap
  12 -> 24 within the unchanged 14 ms budget. Owner SW arrival, same 2,850 keys:
  initial set ready 4.78 -> 3.74 s, queue p95 123 -> 35 ms, request-to-apply p95
  139 -> 45 ms; walkable gate 1.07 -> 1.11 s; per-frame apply p95 0.73 ms.
- Core composer: mouth-support segments filtered by tile bounds, mouth relief result reused
  (route checks -80/-87% in passage tiles). Hashes identical W1/W8/W12, Clang and GCC.
- Opt-in per-tile composer counters. Verify control meshes stored as .xz (78.5 -> 18.4 MB).
- Fast tier 269 PASS.

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

Standalone/Source/StreamBenchmarkHeadless.cpp

@@ -46,6 +46,7 @@ namespace
         bool ScreenSpaceGate=false;
         bool AuditUniformBlockProofs=false;
         bool ProfileLodWork=false;
+        bool ProfilePassageComposer=false;
         bool InstrumentTileDrain=false;
         bool ExactMidpointDensityMemo=false;
         bool ActiveLaneBatching=false;
@@ -1439,6 +1440,7 @@ namespace
                     "  --audit-uniform-block-proofs (fill and check every interval-certified block)\n"
                     "  --profile-lod-work (report per-LOD density sample counts)\n"
                     "  --instrument-tile-drain (opt-in CpuTileTimeline and per-tile stages/counters)\n"
+                    "  --profile-passage-composer (emit per-tile passage work counters)\n"
                     "  --exact-midpoint-density-memo (exact-input midpoint query memo A/B)\n"
                     "  --active-lane-batching --proof-block-cells=N (proof-masked density fill A/B)\n"
                     "  --parallel-sign-edge-repair --serial-sign-edge-repair\n"
@@ -1494,6 +1496,8 @@ namespace
             else if(arg=="--audit-uniform-block-proofs")options.AuditUniformBlockProofs=true;
             else if(arg=="--profile-lod-work")options.ProfileLodWork=true;
             else if(arg=="--instrument-tile-drain")options.InstrumentTileDrain=true;
+            else if(arg=="--profile-passage-composer")
+            {options.ProfilePassageComposer=true;options.InstrumentTileDrain=true;}
             else if(arg=="--exact-midpoint-density-memo")options.ExactMidpointDensityMemo=true;
             else if(arg=="--active-lane-batching")options.ActiveLaneBatching=true;
             else if(arg=="--parallel-sign-edge-repair")
@@ -2214,5 +2218,5 @@ int main(int argc,char** argv)
         options.ProofBlockCells,options.HasSignEdgeRepairOverride
             ?options.ParallelSignEdgeRepair:options.FloatingIslandsRecipe,
         options.AuditNativeLattice,options.LatticeOrphanControl,
-        options.CaptureSkipWalkability);
+        options.CaptureSkipWalkability,options.ProfilePassageComposer);
 }