bug: Art插件无法使用

### 问题描述 / What happened

对话调用Art插件，提示已调用，但反馈主机暂时无法获取可用的图像模型目录，因此这次立绘生成失败了，并非 Art 插件缺少绘图能力。

### 环境 / Environment

- Cindy 版本0.1.30
- PC端MAC端都有此问题

### 复现步骤 / Steps to reproduce

1.安装Art插件
2.调用Art插件对话绘制立绘

### 日志与截图 / Logs & screenshots

_No response_

Start by reproducing the failure with Cindy 0.1.30 on both PC and macOS using the Art plugin and the conversation steps in the report. Inspect the host response and relevant logs to determine why the available image-model catalog cannot be retrieved; done means Art can obtain the catalog and generate a portrait successfully.

Written by the indexing model from the issue text.