Brummel
07ba20a991
`aura --help` and `aura -h` are a newcomer's reflex first command, but today they hit the unknown-subcommand error path: exit 2, empty stdout, one-line `aura: usage: aura run` on stderr. For a C22 "newcomer sees a populated trace" milestone the conventional help affordance returning the error path is a first-contact friction. This compile-clean RED pins the desired success-path contract: `--help` and `-h` print non-empty usage to stdout and exit 0, and the usage names the `run` subcommand. A negative-preservation assertion keeps an unknown subcommand (`frobnicate`) on the exit-2 error path so the fix cannot regress bad-args handling. Asserts structural facts only (exit code, non-empty stdout, mentions `run`), not exact help prose. refs #20