Review found that skipping only in the delete loop under-prunes when sort
is wrong, and excluding TAG before the retain slice would permanently keep
retain+1 releases. Force this run's tag to the front of the sorted list
before slicing so it always has a retain seat and oldest builds still prune.
Also gate prune on publish_live success and warn if TAG still appears stale.
Jinjing
5f6cdb7e61