On a starved CPU, jest force-stopped worker processes that could not exit
within the 500 ms it allows, and script/lib/jest.js failed the run although
every test passed. No test leaks a handle; exit time grows with what a
worker holds, 380 to 970 MB at the end of the run.
workerIdleMemoryLimit in package.json replaces a worker whose heap is over
200 MB after a test file with a fresh one.
tests/jestRunner.test.js runs script/lib/jest.js on a fixture that leaves
an interval running and expects the force-stop to fail the run.
Model: opus-5-5
