fix(storefront): polish cart

Fix real regression: the payment success checkmark and timeout clock
icons had been corrupted to literal '?' glyphs (confirmed via git
history — ✓ and ⏱ were replaced), so a customer who just paid saw a
confusing '?' instead of a success indicator. Restored both icons and
marked them aria-hidden since the adjacent heading already conveys
the status.

Add missing accessible names to icon-only buttons that had none:
quantity increase/decrease controls and the mobile delete button
(desktop remove button had a title attribute only, which is not
reliably announced by screen readers — added aria-label alongside it).
New cart.increaseQuantity/decreaseQuantity keys added across all
three locales.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/i18n/ru.ts

@@ -105,6 +105,8 @@ export const ru: Translations = {
     autoClose: 'Окно закроется автоматически...',
     confirmClear: 'Вы уверены, что хотите очистить корзину?',
     removeItem: 'Удалить товар',
+    increaseQuantity: 'Увеличить количество',
+    decreaseQuantity: 'Уменьшить количество',
     paymentQrAlt: 'QR-код для оплаты',
     acceptTerms: 'Пожалуйста, примите условия оферты, политику возврата и возврата для подтверждения оформления заказа.',
     copyError: 'Ошибка копирования:',