The caching worker controls every page once it registers, and Playwright's
page.route() does not see the fetches a worker makes — so the failed-load test,
which forces a 500 to check the error path, got the real 200 through the worker
and read as a broken feature. Block the worker by default and turn it back on only
for the offline test, which is the one that needs a real one.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
