Canteen Management

Ring a staff meal against the employee's month.

• POS Employee tab: scan or type a card number, see the employee, the rule and how much of the month's cap is left.
• The quote shows the subsidy live, but the final figure is recomputed under the employee account row lock inside the sale transaction, so two tills cannot both take the last of a cap.
• Lock order written down: employee account, then day lock, then bill counter.
• Refusals (no rule, cap reached, card not usable) shown in the portal's own wording.
• Race tests run many concurrent sales and were checked by removing the lock and seeing them fail.

Built and tested on integration/canteen-v1; merge to dev pending.