update detail layout
disable user interaction on detail page
relax slot controller methods to public
construct delegation from card controller to slot controller after card removed for refreshing slot view
update last viewing id of bucket after swiping down
add entry for updating state (card list, current cid and last cid in bucket) after card removed from current bucket)
add api for updating last viewing card idx (sidx) in bucket
update xib
update card/bucket state after card is promoted/downgraded. then trigger redraw