[Bug] hubble1.5.0 执行创建顶点语句报错Undefined vertex label: '??'

### Bug Type (问题类型)

exception / error (异常报错)

### Before submit

- [X] I had searched in the [issues](https://github.com/apache/hugegraph-toolchain/issues) and found no similar issues.

### Environment (环境信息)

- hugegraph 版本:1.2.0
- hugegraph-hubble版本: 1.5.0
>通过docker部署

### Expected & Actual behavior (期望与实际表现)

执行创建顶点语句,报错 Undefined vertex label: '??'
```
g.addV('地点').property(id, '17700').property('name', '海南')
```

我使用HugeGraph Java Client 执行同样的语句能成功.

### Vertex/Edge example (问题点 / 边数据举例)

_No response_

### Schema [VertexLabel, EdgeLabel, IndexLabel] (元数据结构)

_No response_

Start by reproducing the reported statement in Hubble 1.5.0 under the Docker deployment, then compare its behavior with the successful HugeGraph Java Client execution. Trace how the Hubble entry point sends the Chinese vertex label and identify where it becomes '??'; done means the statement creates the vertex without an undefined-label error.

Written by the indexing model from the issue text.