Validated on a 17-PR combined board: compression-worker + colocate-standalone-esm-scope within the board's 287/287, typecheck:core clean, env-doc-sync clean. Offloads eligible sync compression engines into a bounded worker_threads pool with a strict serializable DTO boundary and fail-open on spawn/worker/timeout failure. Closes#11023. Thank you @RaviTharuma!
