A machine with millions of files never finished the walk within fifteen
minutes, so its agent account was never judged and the router refused to
link. Only root can make a setuid-root file, so a complete search stays
sound until root acts: it now runs at idle priority with no bound, is kept
beside the engine's state, judges for rootsearch.FreshFor from its start,
runs again daily and after an apply that moves accounts, packages, actions
or sudo rules, and an incomplete or stale search is never free.