feat: YooKassa webhook, payment timeout, reserved status, BookingConfirmPage

- Add YooKassa webhook handler (POST /api/yookassa/webhook) that updates
  booking to confirmed+paid on payment.succeeded, cancelled on payment.canceled
- Add public status endpoint GET /api/online-bookings/:id for return URL polling
- Add 'reserved' booking status (violet) shown in calendar while awaiting payment
- Add 'website' to BookingSource type
- Payment timeout job (every 2 min) auto-cancels expired unpaid bookings
- Widget setting: "Время ожидания оплаты" (5–60 min, default 15)
- BookingConfirmPage at /booking-confirm/:id — polls status, countdown timer,
  shows success/pending/cancelled state
- Widget bookings now use status='reserved' instead of 'inquiry' when YooKassa
  is configured; set to 'confirmed' by webhook on payment.succeeded
- Migration 070: add 'reserved' to bookings status constraint + payment_expires_at

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/pages/BookingWidgetStandalonePage.tsx

@@ -19,6 +19,7 @@ export function BookingWidgetStandalonePage() {
     showRental:      searchParams.get('rental') === 'true',
     roomDisplayMode: (searchParams.get('mode') ?? 'rooms') as 'rooms' | 'categories',
     minNights:       parseInt(searchParams.get('min-nights') ?? '1') || 1,
+    paymentTimeout:  15,
     paymentProvider: 'yukassa',
     showPromo:       searchParams.get('promo') !== 'false',
     allowExtraBeds:  searchParams.get('extra-beds') !== 'false',