Improve error handling and documentation for Supabase email confirmation requirement

[SwinginLouie]

When setting up the project for the first time, users must enable email confirmation in Supabase's authentication settings. This requirement is not documented and lacks proper error handling, leading to a confusing user experience.

Steps to reproduce

1. Clone repo and follow initial setup
2. Create Supabase project
3. Attempt to register new users
4. Users cannot sign in but receive unclear error messaging

Suggested solutions

Documentation

• Update setup documentation to include:
  • Navigate to Supabase Authentication settings
  • Disable "Confirm email" checkbox

Error Handling Improvements

1. Add explicit error checking for unconfirmed email status
2. Display user-friendly error messages explaining:

• Email confirmation is required
• Instructions to check inbox and spam folder
• Option to resend confirmation email

3. Implement a proper loading state during authentication

[biwasbhandari]

Thank you for the issue. However, we are using the Xverse Wallet (https://www.xverse.app/) for logging in, while leveraging the functionality of Supabase authentication. Since we aim to provide a seamless login experience for users, we do not intend to use email and password authentication at this time.