skip: sound whole-tile proofs for legacy FI/TN/VS fields (L74); FI -30%, TN -22%

The compiled-analytic stratum interval now certifies a legacy tile uniform only when it stays
beyond the detail envelope (and smooth-min slack for solid) with no intersecting primitive,
edit, native field, composer candidate, passage or active transition; everything else fails
closed. The stream layer uses the proof for whole-tile skips; legacy sub-tile skips stay off
(two block proofs failed the falsifier in TN).

Falsifier: full-grid reference vs skip-enabled run, identical mesh/payload/topology hashes on
every tile of all four owner views, Clang and GCC, W1/W8/W12; 20-camera sweep per strate,
0 violations; a too-tight control changed 3/184/233/238 tiles and was caught.
Whole view (8 workers): SW 2.61->2.48, FI 7.18->5.05, TN 5.97->4.63, VS 2.70->2.40 s.

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

Standalone/Source/StreamingWorld.h

@@ -454,13 +454,15 @@ public:
                                            VoxelForgeCore::World* InCoreWorld=nullptr,
                                            bool bInCaptureColumnCoordinates=false,
                                            int32 InLod8HorizonInteriorStepVoxels=0,
-                                           bool bInSharedColumnCache=true)
+                                           bool bInSharedColumnCache=true,
+                                           bool bInAllowUniformSkipsWhenHashing=false)
         :World(&InWorld),WorkerCount(FMath::Clamp(InWorkerCount,1,16)),bHashDensity(bInHashDensity),
          MeshCache(InMeshCache),MaxLevelFilter(InMaxLevelFilter),
          CoreWorld(InCoreWorld),bSkipUvAndColors(bInSkipUvAndColors),bSkipMaterialGroups(bInSkipMaterialGroups),
          bSkipUV(bInSkipUV),bSkipColors(bInSkipColors),
          bCaptureColumnCoordinates(bInCaptureColumnCoordinates),
          bSharedColumnCache(bInSharedColumnCache),
+         bAllowUniformSkipsWhenHashing(bInAllowUniformSkipsWhenHashing),
          Lod8HorizonInteriorStepVoxels(std::max(0,InLod8HorizonInteriorStepVoxels))
     {
         VoxelGenLOD::InitializeConsoleSwitches();
@@ -888,6 +890,7 @@ private:
             VoxelForgeCore::TileGenerationOptions Options;
             Options.bandMinZVoxel=Job.BandZMin;Options.bandMaxZVoxel=Job.BandZMax;
             Options.hashDensity=bHashDensity;
+            Options.allowUniformSkipsWhenHashing=bHashDensity&&bAllowUniformSkipsWhenHashing;
             Options.skipUvAndColors=bSkipUvAndColors;
             Options.skipMaterialGroups=bSkipMaterialGroups;Options.skipUv=bSkipUV;Options.skipColors=bSkipColors;
             Options.captureColumnCoordinates=bCaptureColumnCoordinates;
@@ -1185,6 +1188,7 @@ private:
     bool bSkipColors=false;
     bool bCaptureColumnCoordinates=false;
     bool bSharedColumnCache=true;
+    bool bAllowUniformSkipsWhenHashing=false;
     int32 Lod8HorizonInteriorStepVoxels=0;
     bool bProfileMesherStages=false;
     bool bInstrumentTileDrain=false;