Help Wanted to Implment Authenitiation

[masum184e]

What to do:

1. Create a simple login and signup flow.
2. Use a mock backend, JSON file, or local storage (if backend not ready).
3. On successful login, store user session info securely (token or flag).
4. Show/hide pages or buttons based on authentication state.

Expected outcome:

• Users can register and log in.
• Auth state persists (until logout or browser close).
• Basic error messages for invalid credentials.