applyRecomputeLatest wrote the .versions latest-version pointer and the
demoted prior version's stamp through UpdateEntry without a following
NotifyUpdateEvent, so neither change entered the metadata log. Across
filers the pointer then lived only on whichever filer ran the mutation,
and ListObjects served by any other filer dropped those objects from a
versioned bucket. Emit the events the way PATCH_EXTENDED already does,
keeping a pre-update image for the notification diff.