Invite a team member

Creates the invitation and emails the person a setup link, the same email the portal sends. name only appears in that email. channels null (default) means every channel. 403 plan_limit_reached when every seat is taken (pending invitations count). 409 already_member or invitation_pending. If the email could not be sent, email_sent is false and invite_link carries the setup link for you to deliver; otherwise the link is never exposed. Requires the admin scope.