Replaces the legacy color-only *.tilemap.json fixtures with baked
2-tile atlas-sets in the new atlases/<id>/{diffuse,height,atlas-json,
lock-json} layout. Stub PNGs are 32x32 solid colors matching the
previous color values; height channel is synthesized L8=0 by the baker.
A scripts/bake.sh re-bake helper drives the atlas-baker tool against
assets/_sources/.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Migrates the test-lib content authored alongside lib-core.maps v0.2.0
into its canonical role=test location. Covers packed-u32 GID encode/
decode round-trip, v1 to v2 schema upgrade, schema-v2 validation,
multi-layer load, multi-atlas resolution, per-layer tile lookup with
tile_at backwards-compat, gameplay queries (is_walkable, blocks_walk,
blocks_sight), layer iteration around the entity slot, and v1 JSON
auto-migration on load. 367 assertions total when run via the engine
test-libs harness.
New fixtures: maps/demo_v2.map.json (4x4 multi-layer with roof) and
assets/tiles/walls_tilemap.tilemap.json (second atlas with wall tiles).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
