Tracks native resource debt from #66 after deterministic fs.watch corpus metadata is cleaned up.\n\nThe logical harness fabricates zero RSS growth and cannot prove native FSEvents ownership. The copied regression warms and measures thousands of watcher create-close-GC cycles with a strict RSS ceiling.\n\nAcceptance criteria:\n- run the exact native Darwin watcher stress test in an isolated subprocess\n- instrument path allocations, CF objects, FSEventStream ownership, JS watcher contexts, abort listeners, and pending close microtasks\n- ensure all resources are released after close and GC\n- keep measured RSS growth within the upstream threshold\n- retain the 40-pass logical watch tranche\n\nParent tracker: #66