wip(assembler): round S13 -- tile cost counted per LOD (diagnostics only, no output change)

Exclusive per-stage tile timers and probes. Findings: LOD0 is MC-exclusive
(10.4 of 14 ms p95, 243 ns/sample); LOD4's 3x cost is column-cache misses
(8,224 vs ~1,600-1,900 at LOD3/5), cap refine secondary; per-tile feature lists
cost ~0.001 ms; cross-worker column repeats common (277k at LOD0). Global octave
drop and stride-2 interpolation probes fail the 2 cm gate. Worker cap 1 kept
(cap 0 worse 40 m/s tick tail). Report: Standalone/Research/WorldAssemblerM3/Round17.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ

Standalone/Source/StreamingWorld.h

@@ -424,13 +424,13 @@ public:
                                            bool bInSkipUV=false,
                                            bool bInSkipColors=false,
                                            VoxelForgeCore::World* InCoreWorld=nullptr,
-                                           bool bInCaptureFarColumnCoordinates=false,
+                                           bool bInCaptureColumnCoordinates=false,
                                            int32 InLod8HorizonInteriorStepVoxels=0)
         :World(&InWorld),WorkerCount(FMath::Clamp(InWorkerCount,1,16)),bHashDensity(bInHashDensity),
          MeshCache(InMeshCache),MaxLevelFilter(InMaxLevelFilter),
          CoreWorld(InCoreWorld),bSkipUvAndColors(bInSkipUvAndColors),bSkipMaterialGroups(bInSkipMaterialGroups),
          bSkipUV(bInSkipUV),bSkipColors(bInSkipColors),
-         bCaptureFarColumnCoordinates(bInCaptureFarColumnCoordinates),
+         bCaptureColumnCoordinates(bInCaptureColumnCoordinates),
          Lod8HorizonInteriorStepVoxels(std::max(0,InLod8HorizonInteriorStepVoxels))
     {
         VoxelGenLOD::InitializeConsoleSwitches();
@@ -799,7 +799,7 @@ private:
             Options.bandMinZVoxel=Job.BandZMin;Options.bandMaxZVoxel=Job.BandZMax;
             Options.hashDensity=bHashDensity;Options.skipUvAndColors=bSkipUvAndColors;
             Options.skipMaterialGroups=bSkipMaterialGroups;Options.skipUv=bSkipUV;Options.skipColors=bSkipColors;
-            Options.captureColumnCoordinates=bCaptureFarColumnCoordinates&&Level==8;
+            Options.captureColumnCoordinates=bCaptureColumnCoordinates;
             Options.lod8HorizonInteriorStepVoxels=Lod8HorizonInteriorStepVoxels;
             std::string Error;
             auto Result=CoreWorld->generateTile(
@@ -971,7 +971,7 @@ private:
     bool bSkipMaterialGroups=false;
     bool bSkipUV=false;
     bool bSkipColors=false;
-    bool bCaptureFarColumnCoordinates=false;
+    bool bCaptureColumnCoordinates=false;
     int32 Lod8HorizonInteriorStepVoxels=0;
     std::atomic<uint64> CacheHitCount{0};
     mutable std::mutex Mutex;