refactor: resolved metre layout is the runtime authority (L41, migration step 3); stamp covers plugin sources; R8

UVoxelStrateManager::Initialize resolves the layout width to integer micrometres before passages or
scheduling; each slot stores physical [bottom, top) bounds, transition mode/width and passage settings;
chunk indices remain a floor-based compatibility projection. The Core adapter derives interiors and L29
bands from those resolved values. verify: full-tier cost baseline is HEAD (or --baseline), tier timeout
7200 s with 1800 s per process; the source stamp now includes the plugin Source tree compiled on Linux
(it previously missed VoxelStrateManager.cpp and friends). Owner hashes identical to L37; fast, medium
and full PASS on a clean rebuild. Unreal manager/adapter edits are uncompiled on Windows.
Research R8: inventory of unit-bearing UPROPERTYs and a custom-version asset migration plan.

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

ARCHITECTURE.md

@@ -2184,6 +2184,37 @@ No Unreal adapter or `VoxelWorld.cpp` change was needed, and the evaluator versi
 L37/L39 owner hashes are the parity baseline; the L40 report records fast, medium, full and paired
 cost evidence.
 
+### 8.51 Resolved metre layout authority — World Assembler M3 L41
+
+`UVoxelStrateManager::Initialize` now resolves the layout in integer micrometres before passages or
+Core work are scheduled. The configured layout width is rounded once to micrometres; legacy height
+and inter-strate gap counts are multiplied by that width. Each slot stores its half-open physical
+interval `[bottom, top)`, height, transition mode/width, copied passage settings and their physical
+dimensions. The effective world seed is captured in the manager before passage generation.
+
+The historical 8 m layout keeps its old placement: the first upper edge is +8 m, and each authored
+chunk of height or gap is exactly 8 m. `TopChunkZ` and `BottomChunkZ` are floor-based projections of
+the resolved interval, including mathematical floor for negative Z. Season schema v2 still validates
+its aligned top/bottom chunk values and stacked order as before, then maps those accepted projections
+to the same physical intervals. L29's facing ceiling/bedrock bands are derived from these physical
+intervals and the copied transition width, so their metre bounds retain the prior chunk-based values.
+
+The Core adapter builds SurfaceWorld and FloatingIslands bounds, shared-layout bands, and resolved
+passage dimensions from the micrometre fields. FI and SW both receive the same
+`LayoutChunkWidthSubvoxels = round(layoutWidthMicrometres * 256 / coreVoxelMicrometres)`; layout
+conversion does not use the owner/Core scale. Owner/Core ratios remain in the legacy FloatingIslands
+parameter adapter for generator dimensions that are still authored in owner voxels. The manager's
+legacy passage builder converts resolved passage micrometres back to owner voxels only at its legacy
+geometry API boundary.
+
+Chunk coordinates remain in `GetStrateForChunk`, `GetGeneratorTypeForChunk`, chunk-parameter queries,
+season-v2 validation, and legacy generator dispatch because those interfaces accept layout-chunk
+indices. Their values are cached projections from the physical slot bounds. World-Z queries and the
+Core snapshot use the half-open metre intervals. L40's bound Core field table remains the native
+per-sample dispatch path; this migration adds no manager lookup to it. The Unreal manager and adapter
+cannot be compiled in this Linux workspace, so their small source changes still need the Windows
+Unreal build before integration.
+
 ## 9. Multiplayer model (listen-server first, dedicated-friendly)
 
 > **Status: transport is DESIGN ONLY — nothing is networked in-tree yet** (no `Replicated`/`HasAuthority`/RPCs; a