fix(deals): end hot deals when the venue closes

[savikthk]

Closes #69

Summary

A hot deal is now over at its end time or at the first closing of the venue after its start, whichever comes first; a deal that started while the venue was closed is over at once; round the clock venues keep the end time. The rule is dealOverAt in TS and the same condition in the deals repository SQL, so the guest link ("Это предложение уже закончилось"), the /eat pick, venue cards and their counter, the cabinet list, status and counter, the one live deal per item rule and booking all agree. Deals already stored with an end after closing are covered by the condition, no data migration. Booking such a deal answers deal_not_active ("Предложение уже закончилось") instead of venue_closed.

Changes

• backend/src/domain/deals.ts: dealOverAt.
• backend/src/repositories/deals.ts: visibility, live, finished, live for item and cancel queries use the effective end.
• backend/src/services/deals.ts: dealStatus takes the venue hours, dealViews loads venues, update treats a deal over by closing as finished.
• backend/src/services/bookings.ts: the deal is checked before the venue hours, dealRunning uses dealOverAt.
• backend/src/services/recommendations.ts, backend/test/venue-bot.ts: new dealStatus signature.
• backend/src/http/schemas/deals.ts, backend/src/http/routes/bookings.ts, openapi.yaml, docs/scenario.md (E9): descriptions.

Testing

• Tests added or updated for the change: domain, catalog (link, venue card, counter, a deal published while closed, past midnight, round the clock), cabinet, booking.
• npm run lint, npm run typecheck and npm test pass locally (backend and frontend), npm run build passes.
• Manual, local API with demo data at 23:24 MSK with a stored deal 21:48-23:59 in «Зерно»: hidden for guests, not active in the cabinet, ended in the finished list, booking it answered 409 deal_not_active; the round the clock «Пенка» still showed its deal.
• Tests changed on purpose: in needs an available item on the menu of an open venue the venue_closed check now uses a regular booking without a deal; dealStatus unit tests pass the venue hours.
• Conflicts with [B16] Горящее предложение можно выставить за пределами часов работы заведения #68 are trivial (adjacent imports and describe blocks); this branch is rebased on main after [B16] Горящее предложение можно выставить за пределами часов работы заведения #68 is merged.