feat: long-stay deposit charge + refunds + auto-confirm widget + white page fix

- Widget white page fix: fallback photo when real rooms have no photos array
- Long-stay deposits: if booking > threshold days and toggle on → full charge instead of hold (bypasses YooKassa 7-day limit)
- DepositSettingsPage: toggle + day threshold input for long-stay full payment
- Refund endpoint: POST /deposit/refund supports full and partial refunds via YooKassa refunds API
- DepositWidget: refund UI for yookassa_charge deposits (full/partial, shows remaining amount)
- partially_refunded status support with badge and "Вернуть ещё" button
- Auto-confirm: webhook now auto-confirms booking status on payment.succeeded for widget bookings
- PaymentSettingsPage: auto-confirm toggle per gateway (shown when booking-widget module active)
- Migration 067: long_stay columns on hotel_deposit_settings, auto_confirm_on_payment on gateways, refunded_amount on deposits

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

src/pages/BookingWidgetPage.tsx

@@ -719,7 +719,7 @@ function WidgetPreview({ settings, slug, realRooms, paymentEnabled }: {
             const isExpanded = expandedRoom === room.id
             const isSelected = selected === room.id
             const curPhoto = photoIndex[room.id] ?? 0
-            const photo = room.photos[curPhoto]
+            const photo = room.photos[curPhoto] ?? { bg: 'from-slate-200 to-slate-300', emoji: '🛏️', label: 'Фото' }
             return (
               <div
                 key={room.id}