wip(unreal): round 3 -- owner's in-game defects classified; opening room fixed; Core biome query

Luna, integration round 3, from the owner's four in-game screenshots:
- Capsule rings at the opening and the shaft continuing through the cave room were Core
  world defects: the synthetic bore is removed and the opening gets a finite origin room
  and floor (solid below). New world version, W1/W8/W16 identical: density
  a8bcb72d41092503, mesh 90f29ba15e24579f, payload 82c6b489e7bb7fd7, topology
  7b99448a1f844f2c.
- B-side landing and surface: headless coverage found no missing tiles or LOD-transition
  gaps (960 / 640 fine tiles compiled after travel); best explained by Core's missing
  SurfaceWorld representation. Null-RHI cannot rule out a presentation-only issue.
- Core mode GetBiomeAtWorldLocation now answers (e.g. Biome_Surface_Plain); biome
  terrain itself is not generated yet (proposal: native Core SurfaceWorld evaluator).
Owner checked the Step29 viewer himself: the surface strate type is absent there too.

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

CODEMAP.md

@@ -820,7 +820,7 @@ second density path.
 | `VoxelForgeWormBlockSkipTest.cpp` | `VoxelForge.Determinism.WormBlockSkipSoundness` | Soundness and coverage of the worker-local worm N1 block proof (`voxel.WormBlockSkip`). |
 | `VoxelForgePlayerFitWindow.h` | — | Shared measurement-window policy for player-fit diagnostics (test/editor side only). |
 
-### 3.13 Core runtime integration (round 2)
+### 3.13 Core runtime integration (rounds 2–3)
 The public Core API is linked as the `VoxelForgeCore` runtime module, with canonical implementation
 sources still under `Standalone/`. UBT validates the 18-row manifest and its shims; BuildHost linked
 the module and passed `CheckCoreSymbols.ps1` against the actual shim objects. See
@@ -842,11 +842,13 @@ sequenced `applyEditTransaction` calls after in-flight Core work drains, then re
 affected keys under a new epoch. Existing streaming anchors participate; the headless move proof
 covers `CollisionOnly` policy.
 
-`-coreworldtest=1` in the BuildHost editor commandlet validates the spawned actor's 2,226 initial
-tiles against standalone Core, expected collision bodies/empty tiles, an anchor move, and a carve
-transaction. `VoxelForge.Determinism.CrossPlatformDigest` is the narrow switch-off baseline; it passes,
-but does not instantiate an actor with the switch false. See the report for that limitation and for
-owner-editor instructions.
+`-coreworldtest=1` in the BuildHost editor commandlet validates initial tiles, expected collision
+bodies/empty tiles, anchor movement, a carve transaction, remote travel to the B landing and surface
+strate, full desired visual-key coverage, neighbour/LOD face coverage, and W1/W8/W16 hash parity.
+It also probes the finite origin landing room and Core-mode biome query. `VoxelForge.Determinism.CrossPlatformDigest`
+is the narrow switch-off baseline; it passes, but does not instantiate an actor with the switch false.
+See the report for that limitation, the changed world hashes, classification evidence, and owner-editor
+instructions. The Core route is opt-in; the legacy path remains the default.
 
 ## 4. The density pipeline (most-edited hot path)