The four named checks live in src/checks/. Keep them pure over workspace + claim so test/checks.test.js can feed fixtures without starting the whole product.

Process spawn (test runner) stays in src/spawn.js.

node --test test/*.test.js
node bin/workproof.js --workspace examples/caught

The caught example must exit 1. The clean example must exit 0.

If you change CLI text, update the README sample so it still matches a real run. test/cli.test.js locks that.