Children whose parent dies are reparented to the guest launchd, and its job
manager only reaps PIDs it has a job record for, so every leftover mldr/CEF
process from a killed client tree stayed a zombie until shutdown. Reap zombies
that launchd owns but does not track on a 5 second timer; tracked jobs keep
their exit status for job_reap(). proc_listpids() is not implemented in Darling
yet, so the scan enumerates the guest PID namespace through /proc.
recover-stale-client now signals the stale tree deepest-first so a live parent
can still reap its own children, and prepare.py repairs interrupted checkouts
and missing Git LFS objects instead of publishing pointer text as a library.