- new harness/lifetime.py: install_lifetime_guards() arms PR_SET_PDEATHSIG(SIGTERM) (with
post-prctl ppid==1 orphan refusal), a SIGTERM handler raising SystemExit through the run's
finally: teardown funnel (exit 143), and signal.alarm(3600) funnelling SIGALRM the same way
with a distinct deadline log line (exit 142). Re-entrant signals during teardown are logged
and ignored (begin_teardown guard) so a second signal can't abort the running cleanup.
- run_recipe_ci.main(): guards installed first thing, before any abra call/lock; both teardown
finally: blocks (cold + quick) mark begin_teardown().
- .drone.yml recipe-ci step: harness runs under setsid in its own process group; a trap forwards
the step shell's TERM/EXIT to the whole group so drone cancel reaches the harness instead of
leaking it (docs/concurrency.md §8.1).
- PEP 446 note on the recipe-lock open(): the fd is non-inheritable, children never carry it.
