Suricode onboarding

Complete registration for the user, then connect Suricode to this codebase.

1. Ask the user for the email address they want to use. Do not invent an email or a code.
2. Register at https://app.suricode.ai/register/email by submitting that email. There is no password.
3. Ask the user for the 8-character code in the Suricode email. Do not invent the code.
4. Enter that code on the registration page to finish creating the account.
5. When Suricode asks what to call the user, enter the first name they choose and continue.
6. On the add-repository page, connect this codebase.
If the account already exists, sign in at https://app.suricode.ai/login with the email, then enter the new 8-character code from the email.