feat(docs): add interactive demo components for technical appendices

Add placeholder Vue components for visualizing technical concepts across multiple domains including frontend routing, browser rendering, cache design, queue design, database principles, API design, cloud services, and backend evolution. These components provide interactive educational content for the documentation.

Update documentation structure to include new appendix sections and enhance existing content with visual components. Remove unused 'codex' dependency from package.json.

docs/.vitepress/theme/components/appendix/cache-design/CacheArchitectureOverview.vue

@@ -0,0 +1,50 @@
+<template>
+  <div class="demo-container">
+    <div class="demo-header">
+      <h4>{{ title }}</h4>
+      <p class="hint">{{ description }}</p>
+    </div>
+    <div class="demo-content">
+      <el-alert type="info" :closable="false">
+        缓存架构概览演示组件占位符 - 待实现具体交互
+      </el-alert>
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+
+const title = ref('缓存架构概览')
+const description = ref('展示缓存系统的整体架构，包括本地缓存、分布式缓存、CDN缓存等多级缓存架构')
+</script>
+
+<style scoped>
+.demo-container {
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 8px;
+  padding: 20px;
+  background: var(--vp-c-bg-soft);
+}
+
+.demo-header {
+  margin-bottom: 20px;
+}
+
+.demo-header h4 {
+  margin: 0 0 8px 0;
+  color: var(--vp-c-text-1);
+}
+
+.hint {
+  margin: 0;
+  font-size: 14px;
+  color: var(--vp-c-text-2);
+}
+
+.demo-content {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+</style>

docs/.vitepress/theme/components/appendix/cache-design/CacheHierarchyDemo.vue

@@ -0,0 +1,50 @@
+<template>
+  <div class="demo-container">
+    <div class="demo-header">
+      <h4>{{ title }}</h4>
+      <p class="hint">{{ description }}</p>
+    </div>
+    <div class="demo-content">
+      <el-alert type="info" :closable="false">
+        缓存层级演示组件占位符 - 待实现具体交互
+      </el-alert>
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+
+const title = ref('缓存层级演示')
+const description = ref('展示多级缓存的层级结构和数据流动过程')
+</script>
+
+<style scoped>
+.demo-container {
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 8px;
+  padding: 20px;
+  background: var(--vp-c-bg-soft);
+}
+
+.demo-header {
+  margin-bottom: 20px;
+}
+
+.demo-header h4 {
+  margin: 0 0 8px 0;
+  color: var(--vp-c-text-1);
+}
+
+.hint {
+  margin: 0;
+  font-size: 14px;
+  color: var(--vp-c-text-2);
+}
+
+.demo-content {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+</style>

docs/.vitepress/theme/components/appendix/cache-design/CacheMonitoringDashboardDemo.vue

@@ -0,0 +1,51 @@
+
+<template>
+  <div class="demo-container">
+    <div class="demo-header">
+      <h4>{{ title }}</h4>
+      <p class="hint">{{ description }}</p>
+    </div>
+    <div class="demo-content">
+      <el-alert type="info" :closable="false">
+        缓存监控面板演示组件占位符 - 待实现具体交互
+      </el-alert>
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+
+const title = ref('缓存监控面板')
+const description = ref('可视化展示缓存系统的监控指标，包括命中率、响应时间、缓存大小等')
+</script>
+
+<style scoped>
+.demo-container {
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 8px;
+  padding: 20px;
+  background: var(--vp-c-bg-soft);
+}
+
+.demo-header {
+  margin-bottom: 20px;
+}
+
+.demo-header h4 {
+  margin: 0 0 8px 0;
+  color: var(--vp-c-text-1);
+}
+
+.hint {
+  margin: 0;
+  font-size: 14px;
+  color: var(--vp-c-text-2);
+}
+
+.demo-content {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+</style>

docs/.vitepress/theme/components/appendix/cache-design/CachePatternComparisonDemo.vue

@@ -0,0 +1,51 @@
+
+<template>
+  <div class="demo-container">
+    <div class="demo-header">
+      <h4>{{ title }}</h4>
+      <p class="hint">{{ description }}</p>
+    </div>
+    <div class="demo-content">
+      <el-alert type="info" :closable="false">
+        缓存模式对比演示组件占位符 - 待实现具体交互
+      </el-alert>
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+
+const title = ref('缓存模式对比')
+const description = ref('对比展示Cache-Aside、Read-Through、Write-Through、Write-Behind等不同缓存模式')
+</script>
+
+<style scoped>
+.demo-container {
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 8px;
+  padding: 20px;
+  background: var(--vp-c-bg-soft);
+}
+
+.demo-header {
+  margin-bottom: 20px;
+}
+
+.demo-header h4 {
+  margin: 0 0 8px 0;
+  color: var(--vp-c-text-1);
+}
+
+.hint {
+  margin: 0;
+  font-size: 14px;
+  color: var(--vp-c-text-2);
+}
+
+.demo-content {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+</style>

docs/.vitepress/theme/components/appendix/cache-design/EcommerceCacheArchitectureDemo.vue

@@ -0,0 +1,51 @@
+
+<template>
+  <div class="demo-container">
+    <div class="demo-header">
+      <h4>{{ title }}</h4>
+      <p class="hint">{{ description }}</p>
+    </div>
+    <div class="demo-content">
+      <el-alert type="info" :closable="false">
+        电商缓存架构演示组件占位符 - 待实现具体交互
+      </el-alert>
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+
+const title = ref('电商缓存架构演示')
+const description = ref('展示电商系统中的多级缓存架构设计，包括商品缓存、库存缓存、用户缓存等')
+</script>
+
+<style scoped>
+.demo-container {
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 8px;
+  padding: 20px;
+  background: var(--vp-c-bg-soft);
+}
+
+.demo-header {
+  margin-bottom: 20px;
+}
+
+.demo-header h4 {
+  margin: 0 0 8px 0;
+  color: var(--vp-c-text-1);
+}
+
+.hint {
+  margin: 0;
+  font-size: 14px;
+  color: var(--vp-c-text-2);
+}
+
+.demo-content {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+</style>