- roomsOverlap: full nesting is legal (islands), edge crossings and
partial overlaps still rejected; polyContainsPoly + islandsOf pure
helpers (+2 unit tests, 94 total)
- draw tool: per-click point-in-room rejection removed, validation at
contour closing; parent rooms with islands render as evenodd paths
(ring fills correctly, island stays clickable through the hole)
- smoke_island_rooms.mjs; smoke_merge_split stale room-count asserts
fixed (rg pushed a 5th room; cancelWhole silently false for ages)
- TESTING/CHANGELOG same-commit
