feat: SAC agent command poll qwinsta/logoff (2.0.39-SAC)

Poll GET /api/v1/agent/commands every SacCommandPollIntervalSec;
execute qwinsta/logoff with run_as from SAC; POST result.

login_monitor.settings.example.ps1

@@ -47,6 +47,8 @@ $DailyReportEnabled = 1
 
 # --- Heartbeat SAC (agent.heartbeat): интервал в секундах; 14400 = 4 ч ---
 $HeartbeatInterval = 14400
+# Poll SAC на команды qwinsta/logoff (сек); см. security-alert-center/docs/agent-control-plane.md
+# $SacCommandPollIntervalSec = 60
 
 # Окно (мин): LastBootUpTime + System 41/1074/6005/6008/6009 → «старт после перезагрузки ОС»
 $StartupRebootDetectMinutes = 5