wip(assembler): round L11 -- fix 24 m+ crossing crash; near ring ready 2x sooner at spawn

Crash: crossing tiles were coalesced into one huge rectangle, and BuildSpatialBins tried to
resize to ~4.3e17 bytes (std::bad_alloc; the L7 32 m failure had the same cause). Analytic
regions now skip unread dense bins and compile in world-aligned 128-voxel pages, published
together; out-of-range keys error before allocation. 24 m, 32 m and 1 km crossings pass
(1 km: 72 pages, peak RSS 700 MiB).
Spawn: World::isTileShapeFree proves LOD0 SurfaceWorld tiles that never read the cave shape;
those start before shape compile, and all others wait. Reviewer W12 no-hash: near ring 0.337 ->
0.159 s, whole view +2.1%. All SurfaceWorld/FloatingIslands hashes unchanged (W1/W8/W12, both
compilers, forced-overlap run). Unreal VoxelWorld.cpp adapter changed but NOT built here.

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

Standalone/Source/StreamBenchmarkHeadless.cpp

@@ -9,6 +9,7 @@
 #include <chrono>
 #include <cmath>
 #include <cstdint>
+#include <ctime>
 #include <cstdio>
 #include <cstdlib>
 #include <filesystem>
@@ -41,6 +42,9 @@ namespace
         bool ScreenSpaceGate=false;
         bool AuditUniformBlockProofs=false;
         bool ProfileLodWork=false;
+        bool RegionCrossing=false;
+        bool AuditTileShapeReadiness=false;
+        int DiagnosticSlowShapeCompileMs=0;
         bool HasSeedOverride=false;
         int SeedOverride=0;
         bool HasRenderDistanceOverride=false;
@@ -106,6 +110,7 @@ namespace
                     "  --workers=N --clip-radius=N --max-clip-level=N --max-level=N\n"
                     "  --camera=X,Y,Z,YAW,PITCH (position in metres) --stream-hash\n"
                     "  --camera-step=X,Y,Z (optional second view step in metres)\n"
+                    "  --region-crossing (compile entering Core regions at the camera step)\n"
                     "  --column-cache=shared|thread-local (default: shared)\n"
                     "  --mesh-export=FILE (write the exact generated tile meshes for offline rendering)\n"
                     "  --profile-column-overlap --far-horizon-lod8-step=N --force-generate\n"
@@ -115,6 +120,8 @@ namespace
                     "  --screen-space-gate (measure display error and historical negative controls)\n"
                     "  --audit-uniform-block-proofs (fill and check every interval-certified block)\n"
                     "  --profile-lod-work (report per-LOD density sample counts)\n"
+                    "  --audit-tile-shape-readiness (run a deliberately mis-marked tile against the native-only guard)\n"
+                    "  --diagnostic-slow-shape-compile-ms=N (diagnostic overlap control; default 0)\n"
                     "  --render-distance-chunks=N (0 disables the extra far ring)\n"
                     "  --tls-probe=N (Linux worker TLS/stack measurement; N=0..12)\n"
                     "  --tls-probe-touch=none|surface-world|floating-islands (first-use probe)\n"
@@ -132,6 +139,8 @@ namespace
             else if(arg=="--screen-space-gate")options.ScreenSpaceGate=true;
             else if(arg=="--audit-uniform-block-proofs")options.AuditUniformBlockProofs=true;
             else if(arg=="--profile-lod-work")options.ProfileLodWork=true;
+            else if(arg=="--region-crossing")options.RegionCrossing=true;
+            else if(arg=="--audit-tile-shape-readiness")options.AuditTileShapeReadiness=true;
             else if(arg=="--auto-surface-camera")options.AutoSurfaceCamera=true;
             else if(arg.starts_with("--recipe="))
             {
@@ -199,6 +208,8 @@ namespace
             {if(!readInt("--max-level=",options.MaxLevel))return false;}
             else if(arg.starts_with("--far-horizon-lod8-step="))
             {if(!readInt("--far-horizon-lod8-step=",options.FarHorizonLOD8InteriorStepVoxels))return false;}
+            else if(arg.starts_with("--diagnostic-slow-shape-compile-ms="))
+            {if(!readInt("--diagnostic-slow-shape-compile-ms=",options.DiagnosticSlowShapeCompileMs))return false;}
             else if(arg.starts_with("--process-affinity=")||arg.starts_with("--process-priority=")
                 ||arg.starts_with("--frame-limit="))
             {
@@ -213,8 +224,11 @@ namespace
         options.ClipRadius=std::clamp(options.ClipRadius,1,64);
         options.MaxClipLevel=std::clamp(options.MaxClipLevel,0,8);
         options.FarHorizonLOD8InteriorStepVoxels=std::max(0,options.FarHorizonLOD8InteriorStepVoxels);
+        options.DiagnosticSlowShapeCompileMs=std::clamp(options.DiagnosticSlowShapeCompileMs,0,30000);
         if(!options.TlsProbeRequested&&options.TlsProbeTouch!="none")
         {std::fprintf(stderr,"--tls-probe-touch requires --tls-probe=N\n");return false;}
+        if(options.RegionCrossing&&!options.HasCameraStep)
+        {std::fprintf(stderr,"--region-crossing requires --camera-step=X,Y,Z\n");return false;}
         if(options.TlsProbeRequested)return true;
         if(!options.WorldAssemblerPrototype||!options.StreamBenchmark||!options.StreamPipeline)
         {
@@ -354,5 +368,7 @@ int main(int argc,char** argv)
         options.ProfileColumnOverlap,options.FarHorizonLOD8InteriorStepVoxels,
         options.MeshCoverage,options.MeshExportPath,options.CameraYawDegrees,
         options.CameraPitchDegrees,options.ScreenSpaceGate,options.UseSharedColumnCache,
-        cameraStepVoxels,options.AuditUniformBlockProofs,options.ProfileLodWork);
+        cameraStepVoxels,options.AuditUniformBlockProofs,options.ProfileLodWork,
+        options.RegionCrossing,options.AuditTileShapeReadiness,
+        options.DiagnosticSlowShapeCompileMs);
 }