Measured against knot's tip, every service went red the moment anyone committed anything — and a signal that is always red is one you stop reading, which is the failure this tool exists to escape. Its first real run called the whole fleet stale over two commits that touched a deploy script and an unrelated file. A box is behind when it is missing a commit that touched ITS paths. The path sets are not invented: session-server's is its own sparse-checkout list, which is the box declaring which files it needs to run. The verdict is reached here rather than taken from silo, because silo has no checkout — the most it can say is whether a sha equals knot's tip, and that is precisely the reading that cried wolf. Unrelated commits are still counted, just reported quietly.