feat: add json-stringify node (#215)

Co-authored-by: zengxiaohui <zengxiaohui@bytedance.com>

frontend/packages/workflow/playground/src/nodes-v2/constants.ts

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
- 
+
 import { VARIABLE_MERGE_NODE_REGISTRY } from '@/nodes-v2/variable-merge';
 import { VARIABLE_ASSIGN_NODE_REGISTRY } from '@/nodes-v2/variable-assign';
 import { LLM_NODE_REGISTRY } from '@/nodes-v2/llm';
@@ -51,6 +51,7 @@ import {
   PLUGIN_NODE_REGISTRY,
   SUB_WORKFLOW_NODE_REGISTRY,
   VARIABLE_NODE_REGISTRY,
+  JSON_STRINGIFY_NODE_REGISTRY,
   // cli 脚本插入标识（import），请勿修改/删除此行注释
 } from '@/node-registries';
 
@@ -69,6 +70,7 @@ import {
 
 export const NODES_V2 = [
   // cli 脚本插入标识（registry），请勿修改/删除此行注释
+  JSON_STRINGIFY_NODE_REGISTRY,
   IF_NODE_REGISTRY,
   INTENT_NODE_REGISTRY,
   SUB_WORKFLOW_NODE_REGISTRY,