Flashing dashboard

With current persistance implementation, if an unauthenticated user goes to dashboard he will be able to see the render dashboard page render for a slight moment.
Fix: Udemy courses for reference (it was somewhere in MERN stack course)

Look at the authentication and routing logic in the frontend code, likely in a React component or route guard. The issue mentions a MERN stack course for reference, so examine how the dashboard is conditionally rendered. Check for any client-side persistence that might briefly show the dashboard before redirecting. The fix involves ensuring the dashboard only renders after authentication is confirmed.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.