fix(storefront): replace hardcoded strings with i18n, neutral empty-state wording

- Route aria-label/alt/title strings (rating, discount, carousel arrows,
  hero slides, dialog close, toast dismiss, QR code, bank payment iframe,
  guest checkout fallback) through the translate pipe/service instead of
  literal English.
- Drop the "Oops!"/"Упс!" apology framing from category/subcategory empty
  states (en/ru/hy) - zero results is not an error.

src/app/pages/cart/cart.component.ts

@@ -499,7 +499,7 @@ export class CartComponent implements OnDestroy {
         price: item.discount > 0 ? item.price * (1 - item.discount / 100) : item.price,
       })),
       customer: {
-        name: this.getTelegramUsername() || 'Guest',
+        name: this.getTelegramUsername() || this.i18n.t('common.guest'),
         email,
         phone,
       },