I believe once upon a time the `SelectedRoom` bindable used to be bound
to `RoomManager.JoinedRoom` or similar. But now it's effectively private
to the lounge subscreen and so a lease is unnecessary.
At this point its primary usage is the daily challenge event feed, but
the leaderboard will be using this too shortly.
Because the playlists results screen that exists in `master` is
hard-coupled to showing the *local user's* best result on a given
playlist by way of hard-coupling itself to the relevant API request,
allowing show of *arbitrary* score by ID requires a whole bunch of
subclassery as things stand. Oh well.
Class naming is... best effort, due to the above.