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/platform/index.ts

@@ -31,3 +31,4 @@ export { useBackButton, useConditionalBackButton } from './hooks/useBackButton';
 export { useMainButton, useSimpleMainButton } from './hooks/useMainButton';
 export { useHaptic, useHapticClick, useHapticFeedback } from './hooks/useHaptic';
 export { useNativeDialog, useDestructiveConfirm, PopupButtons } from './hooks/useNativeDialog';
+export { useNotify } from './hooks/useNotify';