fix(scripts): emitPrefabJson rootNode._children 必须包含 group-X 节点 (Task 9 fix round 1)

cocoscreator_projects/framework-tests/legacy-layer-migration/poc-iconbutton.test.mjs

@@ -29,3 +29,16 @@ test('Layer00619 端到端生成 + 校验关键字段', () => {
   const groupNode = json.find(o => o.__type__ === 'cc.Node' && o._name === 'group-55');
   assert.ok(groupNode, '应有 group-55 父节点');
 });
+
+test('Layer00619 端到端 - root._children 包含 group-55', () => {
+  execSync(`${CLI} ${INPUT} ${TARGET} ${OUTPUT_DIR}`, { stdio: 'pipe' });
+  const json = JSON.parse(readFileSync(OUTPUT, 'utf8'));
+  const rootNode = json.find(o => o.__type__ === 'cc.Node' && o._name === 'BackHall_Layer');
+  const groupNode = json.find(o => o.__type__ === 'cc.Node' && o._name === 'group-55');
+  assert.ok(rootNode, '应有 root node');
+  assert.ok(groupNode, '应有 group-55 node');
+  // The fix: root._children must reference group-55
+  const childIds = (rootNode._children || []).map(c => c.__id__);
+  assert.ok(childIds.includes(json.indexOf(groupNode)),
+    `root._children must include group-55 reference; got [${childIds.join(', ')}]`);
+});

cocoscreator_projects/scripts/legacy-layer-to-cocos-prefab.mjs

@@ -614,7 +614,9 @@ export function emitPrefabJson(layer) {
   for (const g of groupParents) {
     const node = makeNode(g.name, { __id__: rootId });
     out.push(node);
-    groupInfo.push({ group: g, node, nodeId: out.length - 1 });
+    const nodeId = out.length - 1;
+    rootNode._children.push({ __id__: nodeId });   // wire group node into root._children (Task 9 fix round 1)
+    groupInfo.push({ group: g, node, nodeId });
   }
 
   // ── 4. Spirit 子节点 + 组件 ────────────────────────────────────