note: Canonical SnS Barge floor plan. 20-person commercial spa program on 60x20 walls / 61x21 slab with literal wall thicknesses (12" exterior, 9" wet/acoustic, 6" dry partitions). Dimensions imported from scripts/schematics/sns_barge_canon.py. This generator was developed under the working name x2_floor_plan.py and promoted to the canonical A1 slot 2026-04-25, replacing the earlier sauna-program A1.
