`count_db_holders` returned None on every non-Linux host, so `hermes doctor`
on macOS (every reporter in the deleted-WAL cluster) printed no
"N process(es) holding the DB open" row. The libproc enumeration that #110544
landed for the sidecar scan already yields `(pid, fd, path, (st_dev, st_ino))`;
count distinct PIDs whose fd identity matches state.db's inode. Identity, not
pathname: libproc reports the path as the opener spelled it (case, symlinked
prefix), which is what the sidecar leg had to case-fold around.
Carries the surviving delta from #110023 (@kshitijk4poor), whose libproc leg
otherwise landed via #110544.
teknium1
b889e4e91c