[client] Always restore Idle on Down despite engine.Stop failure

Log engine.Stop() errors during cleanupConnection instead of returning
early, so beginDown always reaches finishDown and the daemon is restored
to Idle. Return ErrServiceNotUp without an error log.

client/server/server.go

@@ -1099,7 +1099,9 @@ func (s *Server) beginDown() (chan struct{}, error) {
 	giveUpChan := s.clientGiveUpChan
 
 	if err := s.cleanupConnection(); err != nil {
-		// todo review to update the status in case any type of error
+		if errors.Is(err, ErrServiceNotUp) {
+			return nil, err
+		}
 		log.Errorf("failed to shut down properly: %v", err)
 		return nil, err
 	}
@@ -1172,7 +1174,7 @@ func (s *Server) cleanupConnection() error {
 	// making the run loop the sole owner of engine shutdown.
 	if engine != nil {
 		if err := engine.Stop(); err != nil {
-			return err
+			log.Errorf("failed to stop engine during cleanup: %v", err)
 		}
 	}