Refactor src/lib.mjs to support dependency injection for cmdCheck, cmdLock, and cmdList.
This allows unit testing without heavy mocking frameworks or side effects.
Add test/lib.test.mjs covering:
- cmdCheck: happy path, paused/excluded agents, unknown agents.
- cmdLock: success, roster check, existing lock check, race check (lost), dry run.
- cmdList: listing locks, empty state.
Coverage for src/lib.mjs is now significantly improved.
Verification: Ran `npm test` and verified all tests pass.
Co-authored-by: PR0M3TH3AN <[email protected]>
