New external site management. New external prober heartbeat feature.

cmd/control-api/main.go

@@ -102,6 +102,9 @@ func runOrchestratorLoop(ctx context.Context, orch *orchestrator.Orchestrator, c
 			if err := orch.SweepStaleHeartbeats(ctx); err != nil {
 				log.Error("sweep stale heartbeats", "err", err)
 			}
+			if err := orch.SweepStaleSiteHeartbeats(ctx); err != nil {
+				log.Error("sweep stale site heartbeats", "err", err)
+			}
 		}
 	}
 }