feat: add drag-and-drop tariff sorting in admin panel

Implement DnD reorder for tariffs using @dnd-kit, matching the
pattern from AdminPaymentMethods. Add updateOrder API method
and i18n keys for all locales.

src/locales/en.json

@@ -1306,6 +1306,9 @@
       "confirmDeleteText": "This action cannot be undone. The tariff will be permanently deleted.",
       "confirmDeleteWithSubscriptions": "This tariff has {{count}} active subscriptions. After deletion, users will need to select a new tariff when renewing.",
       "deleteSuccess": "Tariff deleted successfully",
+      "saveOrder": "Save order",
+      "orderSaved": "Order saved",
+      "dragToReorder": "Drag to reorder",
       "days": "days",
       "days_one": "{{count}} day",
       "days_other": "{{count}} days",

src/locales/fa.json

@@ -1012,6 +1012,9 @@
       "confirmDeleteText": "این عمل قابل بازگشت نیست. تعرفه برای همیشه حذف می‌شود.",
       "confirmDeleteWithSubscriptions": "این تعرفه {{count}} اشتراک فعال دارد. پس از حذف، کاربران هنگام تمدید باید تعرفه جدید انتخاب کنند.",
       "deleteSuccess": "تعرفه با موفقیت حذف شد",
+      "saveOrder": "ذخیره ترتیب",
+      "orderSaved": "ترتیب ذخیره شد",
+      "dragToReorder": "برای تغییر ترتیب بکشید",
       "days": "روز",
       "days_other": "{{count}} روز",
       "tabs": {

src/locales/ru.json

@@ -1824,6 +1824,9 @@
       "confirmDeleteText": "Это действие нельзя отменить. Тариф будет удалён навсегда.",
       "confirmDeleteWithSubscriptions": "У этого тарифа {{count}} активных подписок. При удалении пользователям потребуется выбрать новый тариф при продлении.",
       "deleteSuccess": "Тариф успешно удален",
+      "saveOrder": "Сохранить порядок",
+      "orderSaved": "Порядок сохранён",
+      "dragToReorder": "Перетащите для изменения порядка",
       "days": "дней",
       "days_one": "{{count}} день",
       "days_few": "{{count}} дня",

src/locales/zh.json

@@ -1050,6 +1050,9 @@
       "confirmDeleteText": "此操作不可撤销。套餐将被永久删除。",
       "confirmDeleteWithSubscriptions": "此套餐有 {{count}} 个活跃订阅。删除后，用户续订时需要选择新套餐。",
       "deleteSuccess": "套餐删除成功",
+      "saveOrder": "保存排序",
+      "orderSaved": "排序已保存",
+      "dragToReorder": "拖动以重新排序",
       "days": "天",
       "days_other": "{{count}} 天",
       "tabs": {