Follow-ups to the salvaged #95947 cron commit:
- Wrap the lock probe in its own try/except: a crashing probe is
'unknown', not 'dead' — the pid scan still decides instead of the
whole tri-state collapsing to None.
- Regression tests (shape adapted from #94155 by @liuhao1024): lock
held + empty pid scan -> alive (the reported false alarm); lock
inactive -> pid-scan fallback both ways; crashing lock probe still
falls back.
- patch_liveness now pins the lock probe inactive by default so the
pre-existing pid-scan tests stay deterministic on machines where a
real gateway holds the real lock.
- contributors mapping for magnus.lundstedt@infidyne.com.
Co-authored-by: liuhao1024 <sunsky.lau@gmail.com>
kshitijk4poor