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/hooks/useNotify.ts

@@ -0,0 +1,92 @@
+import { useCallback } from 'react';
+import { usePlatform } from '@/platform/hooks/usePlatform';
+import { useToast } from '@/components/Toast';
+
+type NotifyType = 'success' | 'error' | 'warning' | 'info';
+
+interface NotifyOptions {
+  type?: NotifyType;
+  title?: string;
+  message: string;
+  duration?: number;
+}
+
+/**
+ * Universal notification hook.
+ * - In Telegram Mini App: uses native showPopup
+ * - In browser: uses Toast component
+ *
+ * @example
+ * ```tsx
+ * const notify = useNotify();
+ *
+ * // Warning notification
+ * notify.warning('Cannot delete: has active subscriptions');
+ *
+ * // Success notification
+ * notify.success('Tariff created successfully');
+ *
+ * // With title
+ * notify({ type: 'error', title: 'Error', message: 'Something went wrong' });
+ * ```
+ */
+export function useNotify() {
+  const { dialog, capabilities } = usePlatform();
+  const { showToast } = useToast();
+
+  const notify = useCallback(
+    (options: NotifyOptions | string) => {
+      const opts: NotifyOptions = typeof options === 'string' ? { message: options } : options;
+
+      const { type = 'info', title, message, duration } = opts;
+
+      // In Telegram - use native popup for important messages
+      if (capabilities.hasNativeDialogs) {
+        dialog.popup({
+          title: title,
+          message: message,
+          buttons: [{ id: 'ok', type: 'ok', text: 'OK' }],
+        });
+        return;
+      }
+
+      // In browser - use Toast
+      showToast({
+        type,
+        title,
+        message,
+        duration: duration ?? (type === 'error' ? 7000 : 5000),
+      });
+    },
+    [capabilities.hasNativeDialogs, dialog, showToast],
+  );
+
+  // Shorthand methods
+  const success = useCallback(
+    (message: string, title?: string) => notify({ type: 'success', message, title }),
+    [notify],
+  );
+
+  const error = useCallback(
+    (message: string, title?: string) => notify({ type: 'error', message, title }),
+    [notify],
+  );
+
+  const warning = useCallback(
+    (message: string, title?: string) => notify({ type: 'warning', message, title }),
+    [notify],
+  );
+
+  const info = useCallback(
+    (message: string, title?: string) => notify({ type: 'info', message, title }),
+    [notify],
+  );
+
+  return {
+    notify,
+    success,
+    error,
+    warning,
+    info,
+  };
+}

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';