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>

CODEMAP.md

@@ -88,19 +88,22 @@ therefore **128 m**, and a 64-chunk strate is **512 m**. Core still stores work
 at 25 cm those tiles happen to span 8 m, but they are not the layout unit. The gameplay capsule remains
 **0.34 m radius / 1.76 m tall** (**2.72 / 14.08 legacy voxels**). Research-field dimensions are authored
 in metres and converted at runtime. The live
-strate generator continues to read voxel-valued parameters from its assets, so those authored
-dimensions become half as large in metres unless their asset values are doubled.
+strate generator continues to read voxel-valued shape parameters from its assets, so those authored
+dimensions become half as large in metres unless their asset values are doubled. U1 adds a
+versioned in-memory conversion for strate height, transition width, and inter-strate gap only; the
+broader Research8 voxel/chunk/centimetre inventory is not yet migrated.
 
 The intended metre-scale families remain: room diameters **8-20 m**, origin hub **24 m**, room cells
 **32 m**, round tunnel bores **3-4 m**, maze cells **16 m** with a **6.25 m nominal bore** (**3.125 m**
 radius; **3.0625 m** worst-case usable floor after roughness), slab open span **22.4 m**, shaft
 diameters **4-7 m**, island diameters **12-24 m**, and ordinary inter-strate bores **3-4 m**. Source
 new fixed physical dimensions are authored in metres and converted to voxel counts at the boundary.
-The owner's voxel-valued live strate assets are not migrated by C++: unchanged saved values therefore
-produce half-size rooms, tunnels, features and noise periods in metres. See the step-3 migration list
-in the handoff report for the exact `DA_Settings` fields and values.
+The owner's voxel-valued live strate shape settings are not migrated by U1: unchanged saved values
+therefore produce half-size rooms, tunnels, features and noise periods in metres. See the U1 report
+for the conversion coverage and remaining Research8 fields.
 
-**Owner asset migration (no packages were edited):** preserve `DA_Settings` distances by changing
+**Prior reauthoring recommendation (not applied in U1; no packages were edited):** preserve
+`DA_Settings` distances by changing
 `ViewDistanceXY 32→64`, `ViewDistanceUp/Down 10→20`, `PawnCollisionRadiusChunks 2→4`,
 `StrateViewMarginChunks 6→12`, `ClipRadius 6→12`, `RenderDistanceChunks 1536→3072`,
 `EdgeSealThickness 128→256 voxels`, decoration radius/near radius `12/6→24/12 chunks`, region
@@ -110,8 +113,9 @@ size `8→16 cells`, spacing/far spacing `8→16 voxels`, march step `4→8 voxe
 `12→24 cells`; it is currently disabled. Keep `MaxClipLevel=6` and zero-valued disabled/unbounded
 limits unchanged; double finite world radii and gaps, and multiply finite voxel-volume caps by 8.
 The loaded `Crystal Cave` slot in `DA_Strate3` is 64 chunks tall; use 128 chunks to preserve its
-former 512 m span. Its voxel-authored live-generator lengths remain half-size until that asset is
-re-authored; the editor-only research field is the step-3 target.
+former 512 m span. U1 automatically converts only strate height and transition widths and the
+settings gap at load; the remaining recommendations above are pending. Its voxel-authored
+live-generator lengths remain half-size until their asset fields are migrated.
 
 Step-3 six-worker scale benchmark (idle machine, `Saved/Research/step3/scale/step3_scale_cacheperf_v1`):
 the 519³ field took **7.133834–7.825292 s** across three runs (median **7.347496 s**); the 259³
@@ -1323,6 +1327,30 @@ See ARCHITECTURE §8.54 and
 [`Standalone/Research/WorldAssemblerM3/Linux58/REPORT.md`](Standalone/Research/WorldAssemblerM3/Linux58/REPORT.md)
 for resolved records, final-field reachability, controls, timing, hashes and captures.
 
+### 3.37 Unreal CoreGeometry assets and partial metre upgrade — World Assembler U1
+
+`Public/VoxelStrateTypes.h` declares optional `FVoxelForgeCoreGeometry`. Its default recipe is Off
+and its stamp, room, and tunnel arrays are empty. `Private/VoxelForgeCoreAdapter.cpp` maps authored
+metres to Core layout requests after passage planning and before finalizing the layout. Stamps use
+the V1 resolver for original stamp kinds and V3 for monolith/platform motifs because the checked-out
+Core API exposes V3; authored cavern records use `ResolveResolvedCavernGraphV1`. Stable feature
+names are namespaced by strate in the resolved layout. `FStrateLandmark::CoreGeometryStableName`
+binds one landmark to such a resolved record, and `VoxelContentManager.cpp` builds its lookup from
+the finalized snapshot. `VoxelWorld.cpp` retains resolved layout identity in content hashing.
+
+`Private/VoxelForgeAssetVersion.h` sets the shared custom version to 2. `UVoxelSettings::Serialize`
+and `UVoxelStrateDefinition::Serialize`/`PostLoad` upgrade only inter-strate gap, strate height,
+and transition width using the saved 8 m layout chunk. These conversions are version-guarded and
+idempotent. No package save is performed by the audit. Other Research8 chunks, owner-voxel lengths,
+Core-voxel lengths/frequencies, and centimetre fields remain on their existing units and need a
+separate migration.
+
+Likely compile/UHT touchpoints are the reflected nested fields in `VoxelStrateTypes.h`, Core snapshot
+and resolver signatures in `VoxelForgeCoreAdapter.cpp`, `FCustomVersionRegistration` and the old
+tunnel-slope version in `VoxelStrateDefinition.cpp`, plus the standalone `VoxelForgeExplore` audit
+in `VoxelForgeExploreCommandlet.cpp`. `GetStrateForChunk` still receives layout-chunk Z, not a Core
+tile index. See `Standalone/Research/WorldAssemblerM3/Unreal1/REPORT.md` for BuildHost evidence.
+
 ## 4. The density pipeline (most-edited hot path)
 
 ### 4.1 `GetDensityWithParams` (TunnelNetwork) — VoxelGenerator.cpp:3749