Tracks Bun corpus position 4228 under #66: js/web/workers/performance-observer-leak.test.ts.
Implemented in 6ab528c:
- Worker-scoped snapshots for Performance entries and registered observers
- automatic disconnect and callback release for Worker-created PerformanceObservers
- removal of Worker-created marks and large detail payloads while preserving parent-realm entries
- PerformanceObserver disconnect, takeRecords, supportedEntryTypes, and performance clearMarks/clearMeasures support
- an active 28-worker lifecycle probe using the upstream virtual worker source
- structured ERR_PERFORMANCE_OBSERVER_LIFECYCLE failures with operation web.performance_observer.dispose, phase, worker count, cause, and source-aware stack
- an exact permanent corpus regression
Verification: 1 pass, 0 todo, 0 fail, 0 unsupported. Neighboring positions 4227–4228: 11 pass, 3 intended debug/ASAN todos, 0 fail, 0 unsupported.