So, this is fun. Apparently "DeckId" is considered preferable to the
"DeckID" were were using until now, and the latest clippy will start
warning about it. We could of course disable the warning, but probably
better to bite the bullet and switch to the naming that's generally
considered best.
- Currently we just use 1.5x and 2x the normal preview delay; we could
change this in the future.
- Don't try to capture the current state; just use a flag to denote
exit status.
- Show (end) when exiting
