add_project_member
Invites by email address. The invitee does not need an account yet.
Email only. There is no invite-by-name, because an invitee may not exist in the
system for a name to be looked up against. Your agent should confirm the address
with you if it is unsure.
remove_project_member
Revokes access immediately.
Destructive and takes effect at once. The conversation history they already
recorded stays in the archive and stays attributed to them; only access is
removed. The project owner cannot be removed.
