Feature Request: add password-less phone number sign up option

although i might be able to achieve it by using a default password for all users
and MFA phone number + sms as real auth method
i'll try later
but having a true password-less experience makes the app experience much more stress-free for users.

No files, tests, or entry points are named. Start by reviewing the existing sign-up and phone/SMS authentication flow, then clarify the intended password-less behavior and acceptance criteria before estimating implementation work.

Written by the indexing model from the issue text.