passkey_last_credential

You cannot remove your only remaining sign-in method.

HTTP status	`409`
`type`	`conflict`
`code`	`passkey_last_credential`
Default message	You can't remove your last sign-in method.

When this happens

You attempted to delete the only passkey on an account that has no linked Google or GitHub identity. Removing it would lock you out.

Add another passkey, or link Google or GitHub from settings, before removing this one.

passkey_signup_email_taken

An account already exists for this email.

passkey_email_send_failed

We could not send the verification email.