Three rule sets open in one repo — Rules, `AGENTS.md`, `CLAUDE.md` — and they will fight. In a fight the model picks a line that compiles. Not necessarily the one you thought was live. The compiling line often also smuggles a bad install. You uninstall it. Cannot uninstall clean, do not make it default. Review cannot say which file it just obeyed. Cannot say, and rollback does not know who to obey. Nobody knows, and five files are harder to pack up.