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

Standalone/Research/WorldAssemblerM3/Research8/shared-notes.md

@@ -0,0 +1,72 @@
+# Unreal asset migration notes — resolved metre layout
+
+Read-only schema review for L41. No Unreal source or assets changed; no build or tests run.
+
+## Existing authored data
+
+- `UVoxelStrateDefinition` is a `UPrimaryDataAsset`. Its persisted `StrateHeightInChunks` and
+  `TransitionBlendChunks` drive the vertical slot and lower-boundary transition. Their comments
+  still describe 4 m chunks, while `UVoxelSettings::StrateLayoutChunkSizeMeters` now defaults to
+  8 m. Keep the numeric fields as legacy authoring inputs and resolve them once using the layout
+  width selected for that world. Do not reinterpret the stored integers as metres or infer their
+  scale from the stale tooltip.
+- `UVoxelSettings::InterStrateGapChunks` is another legacy chunk input. Per-strate
+  `FStratePassageConfig` is persisted with radii, reaches, placement distances, wander, wobble,
+  spiral radius and cascade ledge expressed in legacy voxels; style, connection count, and segment
+  counts are dimensionless/discrete. Retain the exact old effective voxel scale for each legacy
+  asset route, convert dimensional values once, then store the resolved physical passage request
+  and derived seed before any jobs are scheduled.
+- L40/R6 confirms FI and SW already receive the same `LayoutChunkWidthSubvoxels` for layout
+  planning. Never apply an owner/Core ratio to layout bounds a second time. Keep that ratio only
+  in the legacy FI parameter adapter; convert passage and layout inputs at their own established
+  unit boundary.
+
+## Season assets need a separate compatibility route
+
+`UVoxelSeasonAsset` embeds the reviewed JSON plus copied schema/season/seed/hash metadata. Current
+manifest schema v2 stores `height_in_chunks`, global `inter_strate_gap_chunks`, per-slot seed and
+`top_world_z`/`bottom_world_z`; the composer derives those bounds with a fixed `* 32` convention.
+The runtime validates those stored bounds against the live layout chunk width. V2 does not carry a
+resolved transition width/band or passage config for generated slots; authored slots recover
+content and passage settings through `source_definition_path`. The asset loader rejects a schema
+version it does not recognize and verifies both hash copies.
+
+For migration, keep a v2 reader/converter that interprets v2 under its original coordinate
+convention, verifies its existing content hash first, then builds the new immutable metre snapshot.
+Do not rewrite the embedded v2 JSON or silently add default passages: either action changes
+identity or geometry. If a season is explicitly re-authored/exported in a new schema, include
+resolved metre bounds, gap, interface transition/band records, per-strate seed and passage settings;
+bump the manifest schema and generate a new canonical content hash. Record the source schema and
+conversion policy in diagnostics so stale or ambiguous assets fail closed rather than guessing.
+
+## Resolved snapshot and edge rules
+
+The game-thread director should publish integer micrometre records before queueing work: half-open
+strate bounds `[bottom, top)`, height, inter-strate gap, transition width, the exact L29 upper/lower
+band bounds and mode, world/strate/passages seeds, and fully resolved passage descriptors. Copy
+the L29 band endpoints and cap rules exactly; do not recompute a second approximation from chunk
+indices in the adapter. Derive legacy chunk fields only as projections for streaming, old Blueprint
+queries and logging.
+
+Use one conversion and edge policy in manager and adapters. For an aligned half-open interval the
+first chunk is `floor(bottom / chunkWidth)` and the inclusive last chunk is `ceil(top / chunkWidth)
+- 1` (equivalently `top / chunkWidth - 1` when aligned). Use mathematical floor / Euclidean
+division for negative Z, not C++ truncation toward zero. Quantize authored metres to integer
+micrometres once with a documented tie rule; avoid converting through float chunk positions and
+rounding again. Test exact lower/upper edges, one micrometre either side, negative boundaries,
+zero gap, and adjacent bands in both adapter and manager.
+
+## Version and identity risks
+
+- Keep authored-schema version, resolved-layout schema, recipe/evaluator version, and source
+  content hash distinct. A derivation-only schema change may alter layout diagnostics; it must not
+  move the owner density/mesh hashes in this pure-refactor step.
+- For old chunk/voxel assets, preserve physical dimensions with a versioned compatibility
+  conversion. Future metre-authored properties should be explicit and versioned; do not overwrite
+  old fields or treat their raw values as metres. Keep original asset paths/values available for
+  rollback and audit.
+- `FStratePassageConfig` currently has no persisted passage seed, and season v2 lacks generated-slot
+  passage descriptors. Derive seeds with the existing stable world-seed/slot/connection salts and
+  record the result in the snapshot; do not base it on UObject pointer or load order.
+- UHT/UBT validation is still required for any reflected schema/property migration. The Linux Core
+  checks cannot validate UObject serialization, cooked season references, or Blueprint compatibility.