Fix a circular reference issue between users and the auth service

src/main.py

@@ -4,7 +4,7 @@ from src.services.router import Router
 from src.services.notifications import NotificationService, get_notification_service
 from src.services.email import EmailService, get_email_service
 from src.services.auth import AuthService
-from src.services.users import UserService
+from src.services.users.service import UserService
 from dataclasses import dataclass
 from src.infra.db import get_database
 from src.infra.users import UserRepoImpl