fix(drag): root node shouldn't trigger reset position (#871)

* fix(drag): root node shouldn't trigger reset position

* fix: test error

packages/canvas-engine/free-layout-core/__tests__/service/workflow-drag-service.test.ts

@@ -322,10 +322,10 @@ describe('workflow-drag-service', () => {
     });
     expect(dragResult).toEqual(true);
     expect(startNode.getData(PositionData).toJSON()).toEqual({
-      x: 140,
+      x: 100,
       y: 100,
     });
-    expect(endNode.getData(PositionData).toJSON()).toEqual({ x: 940, y: 100 });
+    expect(endNode.getData(PositionData).toJSON()).toEqual({ x: 900, y: 100 });
   });
   it('startDragSelectedNodes with same parent', async () => {
     await document.fromJSON({

packages/canvas-engine/free-layout-core/src/service/workflow-drag-service.ts

@@ -597,7 +597,7 @@ export class WorkflowDragService {
       return;
     }
     const sourceContainer = nodes[0]?.parent;
-    if (!sourceContainer) {
+    if (!sourceContainer || sourceContainer.flowNodeType === FlowNodeBaseType.ROOT) {
       return;
     }
     const valid = nodes.every((node) => node?.parent === sourceContainer);