Add role-based access control and consistent header UI for website

- Add role-based access control: brokers cannot access player.html and players cannot access broker.html
- Update profile.html header to match player/broker dashboard style with dropdown menu
- Update wallet.html header to match player/broker dashboard style with dropdown menu
- Remove hardcoded player.html link from profile.html, use role-based dashboard link
- Fix authentication token key consistency (authToken instead of access_token)