Add `enodia-sentinel status [--json]` — a local health and alert
summary: daemon running state, heartbeat freshness, per-severity alert
counts, last alert time, and eBPF state. Reuses web.daemon_status (the
same data behind /api/status), so the CLI and dashboard never diverge.
Exit code reflects health (0 = running and fresh, 1 = down or stale), so
it doubles as a cron/monitoring probe. Three CLI tests drive it against a
temp log_dir; no daemon or root needed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
