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/stores/stats.js

@@ -6,7 +6,7 @@ export const useStatsStore = defineStore('stats', {
     items: {
       orders_count: null,
       orders_total_amount: null,
-      order_products_count: null,
+      customers_count: null,
     }
   }),
 
@@ -15,7 +15,7 @@ export const useStatsStore = defineStore('stats', {
       const response = await apiPost('getDashboardStats');
       this.items.orders_count = response.data?.data?.orders_count;
       this.items.orders_total_amount = response.data?.data?.orders_total_amount;
-      this.items.order_products_count = response.data?.data?.order_products_count;
+      this.items.customers_count = response.data?.data?.customers_count;
     }
   },