feat(customers): track order meta and OC sync

- add telecart_order_meta table and orders_count column for customers
- introduce OcCustomerService and OrderMetaService for syncing OC data
- rework OrderCreateService transaction flow, metadata handling and tests
- increment telegram customer orders_count and expose it via handlers/UI
- update stats dashboard with rub formatting, tooltips and customers count
- sync SPA theme colors with Telegram WebApp and fix dark variant behavior
- add helpers for RUB formatting and bool casting; simplify logs handler

frontend/admin/src/utils/helpers.js

@@ -5,3 +5,11 @@ export function getThumb(imageUrl) {
   const filename = imageUrl.substring(0, extIndex);
   return `/image/cache/${filename}-100x100${ext}`;
 }
+
+export function rub(value) {
+  return new Intl.NumberFormat('ru-RU', {
+    style: 'currency',
+    currency: 'RUB',
+    maximumFractionDigits: 0
+  }).format(value);
+}