fix: harden desktop monitoring recovery

server/internal/tenant/app/monitoring_service.go

@@ -993,24 +993,21 @@ func (s *MonitoringService) CollectNow(
 	phase2DispatchReady := executionOwner == "desktop_tasks"
 	if len(phase2TaskSpecs) > 0 {
 		phase2TaskCount := len(phase2TaskSpecs)
-		publishedTasks, fallbackLegacyTaskIDs, dispatchErr := s.dispatchMonitorDesktopTasks(ctx, phase2TaskSpecs)
+		publishedTasks, deferredTaskIDs, dispatchErr := s.dispatchMonitorDesktopTasks(ctx, phase2TaskSpecs)
 		if dispatchErr != nil {
-			if fallbackErr := s.fallbackMonitorDesktopTasksToLegacy(ctx, monitorDesktopTaskSpecIDs(phase2TaskSpecs)); fallbackErr != nil {
-				return nil, fallbackErr
-			}
 			phase2DispatchReady = false
 			phase2TaskSpecs = nil
 			if s.logger != nil {
-				s.logger.Warn("phase2 monitor desktop dispatch failed, falling back to legacy execution",
+				s.logger.Warn("phase2 monitor desktop dispatch failed; pending tasks will retry when a desktop client is online",
 					zap.Error(dispatchErr),
 					zap.Int("phase2_task_count", phase2TaskCount),
 				)
 			}
 		} else {
-			if len(fallbackLegacyTaskIDs) > 0 {
-				if fallbackErr := s.fallbackMonitorDesktopTasksToLegacy(ctx, fallbackLegacyTaskIDs); fallbackErr != nil {
-					return nil, fallbackErr
-				}
+			if len(deferredTaskIDs) > 0 && s.logger != nil {
+				s.logger.Info("phase2 monitor desktop tasks deferred until a desktop client is online",
+					zap.Int("deferred_task_count", len(deferredTaskIDs)),
+				)
 			}
 			phase2PublishedTasks = publishedTasks
 		}