Pass the fake descendant the parent process's stdout and stderr stream handles instead of Unix-style numeric file descriptors. This lets Windows duplicate the live ACP and diagnostic pipes so launcher shutdown can prove that inherited handles, buffered frames, and stderr all drain after the parent exits.
Observe the pending update promise before initiating shutdown as well, preventing a missing late frame from becoming a transient unhandled rejection before the assertion reports the fixture failure.
Treat a fallback kill refusal as successful termination when the child already carries an OS exit marker. Windows maps Node's supported signal names to forced termination, so the requested signal can end the process between the launcher error race and its fallback SIGKILL.
Drain inherited stdio, the ACP parser, and in-flight callbacks before propagating the original child error in either exit-race path. Preserve AggregateError reporting only for a refused fallback while the process is still live, and add a deterministic cross-platform regression for that ordering.
Copy an existing target's DACL onto the empty staging file before any content is written, then publish with ReplaceFileW so Windows replacement keeps the target security descriptor instead of inheriting the broader parent policy.
Keep new-file inheritance and POSIX mode behavior unchanged, retain the already-protected temp when a concurrently removed target requires rename fallback, and translate native errors into Node-style codes for the filesystem error boundary.
Add host-independent Win32 binding coverage, native Windows descriptor assertions, package documentation, and a bilingual implemented RFC that supersedes the earlier inheritance-only replacement claim.
Pass an explicit Linux platform to the two remaining SIGTERM-specific ladder tests instead of inheriting the host platform.
This keeps their synchronous-exit assertions focused on the POSIX middle and final rungs while the dedicated Windows case continues to verify the direct SIGKILL path.
Without the pin, native Windows coverage deterministically expected SIGTERM but observed the intended SIGKILL-only behavior.
Observe signal errors and bound the final forced-exit edge with disposeGraceMs so a refused or ineffective SIGKILL cannot leave disposal pending forever.
Apply the confirmation bound on POSIX and Windows, remove listeners and timers on every outcome, and update the ACP consumer contract plus the generated config catalog.
Cover emitted signal errors, synchronous kill exceptions, refused termination, and accepted termination that never reports exit.
