Need to add user models, including a per-user notification queue.

Also need new events for ListShared (or UserAdded, can't decide which).

Also need to think about commands, since the local client can't create share links. (But most traffic from local client will still be events, as the thing will have happened by the time the server funds out about it)

Rule: The local client is the source of truth.

is there any need for lists to have a clock? Yes, need to be able to order events well enough that lists are consistent between users.