One test file. Spawns `opencode <cmd> --help` for every documented
command + key subcommand (35 in total) in parallel under concurrency:8,
snapshots the stderr output (yargs writes --help to stderr, not stdout).
Snapshots are normalized — the tmpdir prefix that bleeds through
`acp --cwd`'s default is rewritten to `<HOME>` so test runs in
different sandboxes stay stable. macOS `/private` realpath form and
the unresolved `os.tmpdir()` form both covered.
Pinned snapshots catch flag removals, renames, reordering, and exit-code
regressions across the entire user-facing CLI surface in one place.
Diff in the .snap file is the surface-change report.
Excluded: `opencode completion --help` is a yargs built-in that emits
top-level help and exits 1; not a real opencode command.
~6s wall-clock thanks to parallel spawns.
Kit Langton