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/VoxelContentManager.h

@@ -340,6 +340,14 @@ private:
         float   SuppressRadiusWorld = 0.0f;
     };
 
+    // Game-thread lookup copied from the immutable resolved Core layout.
+    // Recherche game-thread copiee depuis la disposition Core resolue et immuable.
+    struct FResolvedCoreGeometryAnchor
+    {
+        int32 StrateIndex = INDEX_NONE;
+        FVector LocalPositionCm = FVector::ZeroVector;
+    };
+
     /** WORKER-THREAD surface find → fills OutSpawns for one cell. SurfaceWorld uses the height oracle
      *  (cheap, O(1)/column); other archetypes ray-march the density column. No UObject access except
      *  Generator (thread-safe). Determinism-critical. Resolves the dominant biome PER COLUMN
@@ -436,6 +444,7 @@ private:
     // (kept until the cell leaves range so the surface-find isn't repeated). Strate-bounded.
     // Keyed by FIntVector(cellX|passageIdx, cellY|side, entryIndex) — lattice cell OR passage endpoint.
     TMap<FIntVector, FLandmarkInstance> LandmarkInstances;
+    TMap<FString, FResolvedCoreGeometryAnchor> CoreGeometryAnchors;
     int32 LastLandmarkStrate = INT32_MIN;   // strate change → wipe + rebuild landmarks
 
     // Set in BeginDestroy; worker tasks check it before touching us.