Hardening state files under /var/log was applying chmod 700 to the parent
directory, which broke syslog/logrotate and other services after agent update.
Phase 4.2: SAC_SUPPRESS_FAIL_COUNT during lifecycle shutdown so restart during SAC deploy does not trip Telegram fallback. Add docs/sac-ingest.ru.md for SAC_TIMEOUT_SEC guidance, smoke test, and release manifest.