refactor: Address technical debt in auth refresh implementation

backend/src/ea_chatbot/api/routers/auth.py

@@ -2,7 +2,7 @@ from typing import Optional
 from fastapi import APIRouter, Depends, HTTPException, status, Response, Request
 from fastapi.responses import RedirectResponse
 from fastapi.security import OAuth2PasswordRequestForm
-from ea_chatbot.api.utils import create_access_token, create_refresh_token, settings
+from ea_chatbot.api.utils import create_access_token, create_refresh_token, decode_access_token, settings
 from ea_chatbot.api.dependencies import history_manager, oidc_client, get_current_user
 from ea_chatbot.history.models import User as UserDB
 from ea_chatbot.api.schemas import Token, UserCreate, UserResponse, ThemeUpdate
@@ -101,7 +101,6 @@ async def refresh(request: Request, response: Response):
             detail="Refresh token missing"
         )
     
-    from ea_chatbot.api.utils import decode_access_token # Using decode_access_token for both
     payload = decode_access_token(refresh_token)
     
     if not payload: