pub fn request_shutdown(stop: &AtomicBool, signal: &str)Expand description
Flip the stop flag and emit a shutdown breadcrumb so an operator
tailing the journal sees a clean stop, mirroring
log_startup_banner. Pulled out of the signal task so the
shutdown decision is unit-testable without delivering a real OS
signal. signal names whatever woke us (e.g. "SIGTERM").