feat: enhance demo components with consistent styling and info boxes

- Add standardized header and info box components to all demo files
- Improve visual consistency with theme colors and spacing
- Add max-height and overflow-y for better content containment
- Update package.json build script with --force flag
- Add .gitignore entries for REFACTORING files
- Fix table formatting in audio-intro.md

docs/.vitepress/theme/components/appendix/cloud-storage-cdn/CachePolicyDemo.vue

@@ -1,14 +1,20 @@
 <template>
   <div class="demo-container">
     <div class="demo-header">
-      <h4>{{ title }}</h4>
-      <p class="hint">{{ description }}</p>
+      <span class="icon">⚙️</span>
+      <span class="title">{{ title }}</span>
+      <span class="subtitle">{{ description }}</span>
     </div>
     <div class="demo-content">
       <el-alert type="info" :closable="false">
         缓存策略演示组件占位符 - 待实现具体交互
       </el-alert>
     </div>
+
+    <div class="info-box">
+      <span class="icon">💡</span>
+      <strong>核心思想：</strong>缓存策略平衡命中率和新鲜度，TTL 设置太短会导致频繁回源，太长会导致内容过期。
+    </div>
   </div>
 </template>