feat: add useNotify hook for unified notifications

- Created useNotify hook (src/platform/hooks/useNotify.ts):
  - In Telegram Mini App: uses native showPopup
  - In browser: uses beautiful Toast component
  - Methods: notify(), success(), error(), warning(), info()

- AdminTariffs: improved deletion UX
  - Uses useNotify.warning when tariff has subscriptions
  - Uses useDestructiveConfirm for delete confirmation
  - Shows success toast after deletion
  - Removed custom modal dialog

- AdminEmailTemplates: unified notification style
  - Replaced dialog.alert with useNotify.warning
  - Now shows beautiful Toast on mobile browser

- Added deleteSuccess i18n translations (ru, en, zh, fa)

src/locales/en.json

@@ -1218,6 +1218,7 @@
       "cannotDeleteHasSubscriptions": "Cannot delete: has active subscriptions",
       "confirmDelete": "Delete tariff?",
       "confirmDeleteText": "This action cannot be undone. The tariff will be permanently deleted.",
+      "deleteSuccess": "Tariff deleted successfully",
       "days": "days",
       "days_one": "{{count}} day",
       "days_other": "{{count}} days",

src/locales/fa.json

@@ -992,6 +992,7 @@
       "cannotDeleteHasSubscriptions": "حذف ممکن نیست: اشتراک‌های فعال وجود دارد",
       "confirmDelete": "تعرفه حذف شود؟",
       "confirmDeleteText": "این عمل قابل بازگشت نیست. تعرفه برای همیشه حذف می‌شود.",
+      "deleteSuccess": "تعرفه با موفقیت حذف شد",
       "days": "روز",
       "days_other": "{{count}} روز",
       "tabs": {

src/locales/ru.json

@@ -1728,6 +1728,7 @@
       "cannotDeleteHasSubscriptions": "Нельзя удалить: есть активные подписки",
       "confirmDelete": "Удалить тариф?",
       "confirmDeleteText": "Это действие нельзя отменить. Тариф будет удален навсегда.",
+      "deleteSuccess": "Тариф успешно удален",
       "days": "дней",
       "days_one": "{{count}} день",
       "days_few": "{{count}} дня",

src/locales/zh.json

@@ -1030,6 +1030,7 @@
       "cannotDeleteHasSubscriptions": "无法删除：有活跃订阅",
       "confirmDelete": "删除套餐？",
       "confirmDeleteText": "此操作不可撤销。套餐将被永久删除。",
+      "deleteSuccess": "套餐删除成功",
       "days": "天",
       "days_other": "{{count}} 天",
       "tabs": {