Currently, invitations are single-user, and also require the admin to enter all user details except for password/passkey.

It would be nice if invitation links could be created that bypass SIGNUP: TRUE and/or SIGNUP_REQUIRES_APPROVAL, but otherwise allow for multiple users to onboard with them.

Perhaps this could be configured with a specific number of uses, but an MVP would simply allow unlimited signups while the link is marked active.

This would allow admins to block signup from the public, but allow it for users where links can be shared through private means.