Three playtest-reported bugs fixed out-of-phase before Phase 18:
* Furniture build-queue gap: Torch / Bed / Crate / Workbench / CremationPyre
were missing World.register_build_site(self) in _ready, so newly-painted
designations never entered ConstructionProvider's iteration. The seeded
cabin pre-built everything via _spawn_complete_* helpers, masking the gap
until a player painted a fresh furniture designation.
* Wall-trap regression for bystanders + walk-through pawns: Wall._complete
now dislodges any pawn on the tile via new Pathfinder.find_nearest_walkable
BFS helper; Pawn._advance_walk re-checks next tile walkability before
stepping, aborts walk + cancels job + lets Decision reroute. Phase 6's
adjacent-stand fix only protected the BUILDING pawn.
* Floor / Pawn Y-sort ambiguity: Floor was anchored at tile-center
(same Y as Pawn), so Y-sort tiebreak fell to scene-tree order and
Floor (spawned later) drew over Pawn. Moved Floor origin to top-of-tile
so Floor.y < Pawn.y under Y-sort; _draw rect offsets compensate.
All three verified via MCP runtime: torch built end-to-end, all 3 pawns
working on different jobs with no idle traps, pawn renders over floor.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>