[Feature] 希望在外观配置中添加字体大小的设置，可自定义界面字体大小，代码字体大小等

### What problem does this solve?

<img width="1100" height="750" alt="Image" src="https://github.com/user-attachments/assets/acecad59-9b33-4a66-aed0-6e8b5ba23319" />

### Proposed solution

可参考 zcode 这一块的设计：

<img width="1262" height="754" alt="Image" src="https://github.com/user-attachments/assets/2beb2753-46c6-448c-9c13-50676c3ed100" />

### Alternatives considered

_No response_