The installed hook exits 0 with one line when ousast (or OUSAST_COMMAND) is
not on PATH, still chaining a prior hook. In Git hook mode without an explicit
--mode blocking, argument/usage errors (an invalid OUSAST_PUSH_DEADLINE, a cache
directory inside the repository, a refused experimental flag) and unexpected
exceptions print one "check did not run" line and exit 0. Blocking mode keeps
its usage errors. Requirement 9.1.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo
