cli: tighten help command-order assertion

[greygoody]

What to build

Tighten the CLI contract test for help ordering so it matches the specific check and ok command rows instead of using loose substring matching.

Acceptance criteria

• The help-surface test matches command rows such as check and ok rather than a broad stdout.find("check").
• The test still proves check is promoted before the compatibility alias.
• No CLI behavior changes.
• cargo fmt --all -- --check passes.
• cargo test --workspace passes.

Blocked by

None - can start immediately.