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/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": {