希望可以支持定制全局主题应用到组件

## 功能建议
在kitchen定制全局主题（比如颜色、圆角、间距等），一键应用到组件。
现在只能用官方主题，希望可以加入定制主题的功能。

Start by reviewing how Kitchen currently applies official themes to components. Define the scope for global customization, including colors, corner radii, and spacing, and determine how one customized theme should be applied across components. Done means users can create a custom global theme and apply it consistently instead of using only official themes.

Written by the indexing model from the issue text.