- 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
