docs: 重构 Git Pages 为技术白皮书风格

## 主要变更

### 架构重构
- 简化主题入口，移除不必要的 Vue 组件
- 合并 CSS 文件为单一 vars.css
- 添加 markdown-it-footnote 学术引用支持
- 添加 Mermaid 深色主题动态切换

### 新增内容模块
- 算法学院 (Academy): 深度算法解析
  - Huffman 编码深度解析（含数学证明）
  - 状态机设计哲学（5状态 FSM）
- 架构设计: 系统分层架构文档
- 参考文献: 学术引用机制

### 工程化改进
- 新增 ci-docs.yml PR 验证工作流
- 更新导航和侧边栏配置
- 添加 footnote CSS 样式

### 移除组件
- CustomFooter.vue (使用默认 footer)
- StatsBar.vue (改为纯 CSS)
- BackToTop.vue, ReadingProgress.vue

参考标杆: kimi-cli 极简工程化方案

Author: LessUp

.github/workflows/ci-docs.yml

@@ -0,0 +1,47 @@
+name: CI Docs
+
+on:
+  push:
+    branches: [main, master]
+    paths:
+      - 'docs/**'
+      - '.github/workflows/ci-docs.yml'
+  pull_request:
+    branches: [main, master]
+    paths:
+      - 'docs/**'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Cache docs node_modules
+        uses: actions/cache@v4
+        with:
+          path: docs/node_modules
+          key: ${{ runner.os }}-docs-node-modules-${{ hashFiles('docs/package.json') }}
+          restore-keys: |
+            ${{ runner.os }}-docs-node-modules-
+
+      - name: Install docs dependencies
+        working-directory: docs
+        run: npm install --no-package-lock
+
+      - name: Build docs
+        working-directory: docs
+        run: npm run build
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: docs-dist
+          path: docs/.vitepress/dist
+          retention-days: 7

docs/.vitepress/config.ts

@@ -1,6 +1,8 @@
 import { defineConfig } from 'vitepress'
 import { withMermaid } from 'vitepress-plugin-mermaid'
 import llmstxt from 'vitepress-plugin-llms'
+import footnote from 'markdown-it-footnote'
+import mark from 'markdown-it-mark'
 
 const rawBase = process.env.VITEPRESS_BASE
 const base = rawBase
@@ -21,6 +23,13 @@ const sharedSidebar = {
         { text: 'Project Structure', link: '/en/guide/project-structure' },
       ],
     },
+    {
+      text: 'Academy',
+      items: [
+        { text: 'Algorithm Academy', link: '/en/academy/' },
+        { text: 'Huffman Coding', link: '/en/academy/huffman' },
+      ],
+    },
     {
       text: 'Algorithms',
       items: [
@@ -51,6 +60,8 @@ const sharedSidebar = {
     {
       text: 'Reference',
       items: [
+        { text: 'Architecture Design', link: '/en/architecture/' },
+        { text: 'Bibliography', link: '/en/reference/bibliography' },
         { text: 'OpenSpec Specs', link: 'https://github.com/LessUp/compress-kit/tree/master/openspec/specs' },
         { text: 'Contributing', link: '/en/guide/contributing' },
         { text: 'Changelog', link: '/en/release-notes/changelog' },
@@ -67,6 +78,14 @@ const sharedSidebar = {
         { text: '项目结构', link: '/zh/guide/project-structure' },
       ],
     },
+    {
+      text: '学院',
+      items: [
+        { text: '算法学院', link: '/zh/academy/' },
+        { text: '霍夫曼编码深度解析', link: '/zh/academy/huffman' },
+        { text: '状态机设计哲学', link: '/zh/academy/state-machine' },
+      ],
+    },
     {
       text: '算法详解',
       items: [
@@ -97,6 +116,8 @@ const sharedSidebar = {
     {
       text: '参考',
       items: [
+        { text: '系统架构设计', link: '/zh/architecture/' },
+        { text: '参考文献', link: '/zh/reference/bibliography' },
         { text: 'OpenSpec 规范', link: 'https://github.com/LessUp/compress-kit/tree/master/openspec/specs' },
         { text: '参与贡献', link: '/zh/guide/contributing' },
         { text: '更新日志', link: '/zh/release-notes/changelog' },
@@ -266,6 +287,10 @@ export default withMermaid(defineConfig({
     languageAlias: {
       cuda: 'cpp',
     },
+    config: (md) => {
+      md.use(footnote)
+      md.use(mark)
+    }
   },
 
   head: [