Allow independently bounded Darwin helper compilation to finish before the five-second Java deadline starts. Keep Linux process-table preparation under command supervision.
Share preparation failure translation between both stages so physical compiler outcomes, exact cancellation reasons and cleanup capabilities retain one owner. Adapt contributor PR #4795 and extend preparation handoff and retry controls.
Fixes#4793
Co-authored-by: J0UH <217747670+J0UH@users.noreply.github.com>
