Features:

- Node group CRUD operations with traffic-based filtering
  - Three grouping modes: average distribution, subscription-based, and traffic-based
  - Automatic and manual group recalculation with history tracking
  - Group assignment preview before applying changes
  - User subscription group locking to prevent automatic reassignment
  - Subscribe-to-group mapping configuration
  - Group calculation history and detailed reports
  - System configuration for group management (enabled/mode/auto_create)

  Database:
  - Add node_group table for group definitions
  - Add group_history and group_history_detail tables for tracking
  - Add node_group_ids (JSON) to nodes and subscribe tables
  - Add node_group_id and group_locked fields to user_subscribe table
  - Add migration files for schema changes

scheduler/scheduler.go

@@ -52,6 +52,12 @@ func (m *Service) Start() {
 		logger.Errorf("register update exchange rate task failed: %s", err.Error())
 	}
 
+	// schedule recalculate group task: every hour
+	recalculateGroupTask := asynq.NewTask(types.SchedulerRecalculateGroup, nil)
+	if _, err := m.server.Register("@every 6h", recalculateGroupTask, asynq.MaxRetry(2)); err != nil {
+		logger.Errorf("register recalculate group task failed: %s", err.Error())
+	}
+
 	if err := m.server.Run(); err != nil {
 		logger.Errorf("run scheduler failed: %s", err.Error())
 	}