fix(unreal): U1 -- Unreal compiles again on L61; CoreGeometry asset section; versioned layout-unit upgrade

Windows MSVC catch-up after abyss L15-L61 (no Unreal there): 64-bit clipmap
shift (C4334), qualified VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel, UHT
metadata and duplicate-signature fixes. Optional CoreGeometry section on
UVoxelStrateDefinition (native caves, lattice, profiled heightfields, named
stamps, rooms/tunnels; off/empty by default), resolved after passage planning.
VoxelForgeAssetVersion 2 converts strate height/transition/gap to metres on
load (exact, 0 m change on the owner's 5 assets; packages never saved).
Gates pass (SurfaceWorld, FloatingIslands, Core-off, M2, W1/W8/W16).
KNOWN REGRESSION vs L14 (2026-10-20, same command, same PC): full set 3.9 ->
5.37 s, worker-seconds 15.8 -> 30, LOD0 1.11 -> 1.69 s, ring 0.50 -> 0.80 s;
not yet attributed (Core L15-L61 vs Unreal side).
Report: Standalone/Research/WorldAssemblerM3/Unreal1.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Source/VoxelForge/Public/VoxelWorld.h

@@ -614,6 +614,7 @@ public:
     FVector GetVoxelForgeCoreDefaultCenterWorld() const;
     bool QueryVoxelForgeCoreDensityAt(FVector WorldLocation, float& OutDensity) const;
     bool GetVoxelForgeCoreWorldAssembly(FString& OutCanonicalJson, FString& OutContentHash) const;
+    bool GetVoxelForgeCoreResolvedLayout(FString& OutCanonicalJson, FString& OutStableIdentity) const;
 
     UFUNCTION(BlueprintPure, Category = "Voxel World|Strate")
     int32 GetStrateAtPosition(FVector WorldPosition) const;
@@ -778,6 +779,8 @@ private:
     TSharedPtr<FVoxelForgeCoreRuntimeState, ESPMode::ThreadSafe> VoxelForgeCoreState;
     FString VoxelForgeCoreWorldAssemblyJson;
     FString VoxelForgeCoreWorldAssemblyHash;
+    FString VoxelForgeCoreResolvedLayoutJson;
+    FString VoxelForgeCoreResolvedLayoutIdentity;
     FVector CoreFallbackCenterLocalCm = FVector::ZeroVector;
     bool bCoreRegionCompilePending = false;
     TArray<FVoxelTileKey> PendingCoreRegionTiles;