Unify email address validation logic on the /signup page between the frontend and the Supabase Auth

[shige]

Task description

Unify email address validation logic on the /signup page between the frontend and the Supabase Auth API.

https://supabase.com/docs/guides/auth

Background

Currently, the frontend and API likely have different email validation implementations on the /signup page. This can lead to inconsistencies in user experience and potentially bypass validation checks. The API should be relying on Supabase Auth's email validation logic. To maintain consistency and ensure proper validation, the frontend should align with the API's (Supabase Auth's) validation rules.

TODO (Optional)

• Investigate the current email validation logic on both frontend and backend.
• Identify the specific validation rules used by Supabase Auth.
• Update the frontend email validation to match Supabase Auth's validation rules.
• Verify that email validation is consistent across the frontend and API.

Additional notes (Optional)

This task may involve modifying frontend code related to form validation, and potentially adjusting any client-side libraries used. It should ensure that error messages displayed to users are consistent regardless of whether the validation fails on the frontend or the API.