refactor: enhance type hinting and casting for improved type safety across multiple files

tests/services/test_auth_service.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 from typing import cast
 from unittest.mock import MagicMock
 
-import pytest  # type: ignore[import-not-found]
+import pytest
 from app.core.security import JWTService, PasswordHasher
 from app.models.user import User
 from app.repositories.user_repo import UserRepository