chore: enhance environment configuration for frontend and Google authentication

- Add VITE_API_URL to docker-compose for frontend service.
- Introduce FRONTEND_URL in backend environment files for redirection after Google login.
- Update Google authentication router to use dynamic FRONTEND_URL for redirects.

backend/api/routers/google_auth.py

@@ -13,6 +13,7 @@ GOOGLE_CLIENT_ID = os.getenv("GOOGLE_CLIENT_ID")
 GOOGLE_CLIENT_SECRET = os.getenv("GOOGLE_CLIENT_SECRET")
 REDIRECT_URI = os.getenv("GOOGLE_REDIRECT_URI")
 SECRET_KEY = os.getenv("SECRET_KEY")
+FRONTEND_URL = os.getenv("FRONTEND_URL", "http://localhost:5173")
 
 @router.get("/login")
 async def google_login():
@@ -97,4 +98,4 @@ async def google_callback(request: Request):
         {"$set": {"token": token}}
     )
 
-    return RedirectResponse(f"http://localhost:5173/login?token={token}")
+    return RedirectResponse(f"{FRONTEND_URL}/login?token={token}")