Jest force-stopped worker processes that could not exit within 500 ms on a starved CPU, failing runs where every test passed. The test scripts now pass --runInBand. script/lib/jest.js fails the run at once when jest warns that it did not exit one second after the run, instead of hanging. The Dockerfile test stage drops its 90-second timeout. tests/jestRunner.test.js runs the runner on a fixture that leaves an interval running and expects exit status 1. Model: opus-5-5