Sample fleet averages every heartbeat flush into fleet_metric_samples;
expose GET /api/servers/fleet-metrics and Dashboard sparkline card (B-02).
Co-authored-by: Cursor <cursoragent@cursor.com>
Unify upgrade-agent with install.sh via agent_deploy; auto-sync Git web/app after
Docker upgrade to prevent vite hash drift; extend prod_probe for Beijing TZ checks.
Co-authored-by: Cursor <cursoragent@cursor.com>