- Add D-230 skeleton: DistrictSkeleton field to DistrictWorldState;
cascade Default to DistrictSkeleton + contained enums/structs. Box the
GenCompletion::SkeletonGenerated state to avoid large_enum_variant.
- Derive PartialEq on FloorExtent/FloorHeightProfile/DistrictWorldState/
CityGenerationContext (+ minimal cascade) for downstream assert_eq tests.
- Add 4 unit tests for floor_at_voxel_z / voxel_range_for_floor (uniform,
basement, variable heights, boundary) — the Q-104 deliverable.
- Drop unused smallvec direct dep (stays transitive via bevy_ecs).
- Key districts insert by skeleton.district_id, sharpen TODO(#957).
clippy --all-targets -D warnings clean; 1263 lib tests pass; fmt clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>