Replace hardcoded uptime (3600s) with real elapsed time tracked via Instant::now() in MonitoringServiceImpl constructor. Surface live kill switch state (active, emergency, unhealthy) as critical_issues strings in GetSystemStatusResponse. Set sysinfo-dependent CPU/memory/disk/network metrics to 0.0 with TODO comments pending sysinfo crate integration. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>