Backoffice stage 3: orders and providers, auto-assignment

- Auto-assignment: a new order is offered to the best free provider (same ranking as
  the dispatcher hint); a decline or timeout passes it to the next one; nobody is
  offered the same order twice; after N tries it waits for a dispatcher and the team
  is notified once. The worker retries waiting orders every minute. Settings
  assign.auto / assign.maxAutoOffers (toggle on the Orders page, checkbox in old admin).
- Orders: list by day with groups (need a provider, offered, assigned, in progress,
  done, cancelled), periods and search; order card with progress, provider or ranked
  candidates ("offer" / "pick automatically"), details, checklist and photos,
  history in plain words, client, money (superadmin), payment, status change,
  reschedule (slots or custom time), cancel with fee.
- New order for a client (from the client card or the Orders page): params form,
  address, free slots for 14 days, price with the client's discount.
- Providers: list with rating, orders, declines, low ratings, next order; card with
  quality, ratings, upcoming orders, schedule and districts, admission documents,
  block/unblock with reason, new bot link, money and payouts (superadmin).
- Payout gets paidAt/note/createdById; Provider gets blockedReason/blockedAt/adminNote
  and documents (ProviderDoc).
- Tests for auto-assignment.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

apps/backoffice/src/main.tsx

@@ -1,6 +1,7 @@
 import '@barev/ui/styles.css';
 import './styles.css';
 import './chats.css';
+import './orders.css';
 import { ApiProvider, ToastProvider } from '@barev/web';
 import { StrictMode } from 'react';
 import { createRoot } from 'react-dom/client';