fix(storybook): use absolute URL for Protocol Demo link

Fixes #12 - Protocol Demo link was not navigating when clicked
because relative path `../` was being intercepted by Storybook's
routing system.

Author: deepracticexc

apps/storybook/src/stories/Introduction.mdx

@@ -8,7 +8,7 @@ import { Meta } from '@storybook/addon-docs/blocks'
 
 UIX 是专为构建 AI Agent 交互界面设计的组件库，基于 **UIX Protocol** 实现 AI 输出到 UI 渲染的标准化转换。
 
-> 💡 查看 [Protocol Demo](../) 了解 UIX 的核心工作原理
+> 💡 查看 [Protocol Demo](https://uix.deepractice.org/) 了解 UIX 的核心工作原理
 
 ## 特性