Inviting staff

1. Staff screen enter an email and Send invitation. The invitation has a link (copy, resend, extend, revoke).
2. The invitee accepts through the link. They then have no permissions until you grant some.
3. On the same screen the owner opens Edit permissions and ticks what that person needs, or Disable to stop access without deleting the row. Only the owner can do this; the API refuses other staff.