Named it "filesystem-groomer" which is terrible but at least it's a name. Watches a directory tree, emits events when parquets land or disappear. Not a database, not an index -- just a thing that notices files and tattles. fanotify on Linux, recursive watches, the usual dance. The interesting part is what it doesn't do, which is everything else. It's a notifier. Resisted the urge to bolt anything more on. For now.
