v0.253.0

In the case where the loggedInUser does not have data storage and has upload access to exactly one other user, set the uploadTargetUser properly on log in/initialization via token.

In the same circumstance, also show a user dropdown with only one user in it to surface the fact tat the uploadTargetUser is not the same as the loggedInUser. [This second was a regression in functionality from 0.242.0.]