Repair Seatwise browser and authoritative planning

Work in the real product frontend and the transactional backend. A party must occupy contiguous columns in one row and its declared size must equal its seat selection. Accessible seats require their configured companion when requested. Charge each selected seat once, apply percentage child discounts with floor rounding, and count confirmed seats individually. The board-to-API adapter and an authoritative planning guard both contain defects. The browser workflow and direct API checks must agree on the same contract. Run bash test/run.sh. The public checks drive Chromium against native HTTP and a real database; each scoring group includes regression safeguards.

Work with the stack you want to practice. Your workspace and timer start after you choose.