feat(docs): enhance interactive demos and improve documentation

- Add new interactive components for frontend routing, browser rendering pipeline, and database transactions
- Improve existing demos with better visuals, explanations, and examples
- Update documentation structure and content for better clarity
- Add new utility scripts and update package.json with new commands
- Fix formatting and alignment in documentation tables

docs/.vitepress/theme/components/appendix/database-intro/DatabaseRelationDemo.vue

@@ -1,50 +1,320 @@
 <template>
-  <div class="demo-container">
+  <div class="relation-demo">
     <div class="demo-header">
-      <h4>{{ title }}</h4>
-      <p class="hint">{{ description }}</p>
+      <span class="icon">🔗</span>
+      <span class="title">外键关系演示</span>
+      <span class="subtitle">理解表与表之间如何关联</span>
     </div>
-    <div class="demo-content">
-      <el-alert type="info" :closable="false">
-        数据库关系演示组件占位符 - 待实现具体交互
-      </el-alert>
+
+    <div class="intro-text">
+      想象你在管理一个<span class="highlight">家族谱系</span>：有"家谱表"记录每个人，有"婚姻表"记录谁和谁结婚了。两张表通过"人名"关联起来，这就是<span class="highlight">外键</span>的作用。
+    </div>
+
+    <div class="tables-container">
+      <div class="table-card users-table">
+        <div class="table-header">
+          <span class="table-icon">👥</span>
+          <span class="table-name">用户表 (users)</span>
+          <span class="table-badge">主表</span>
+        </div>
+        <div class="table-content">
+          <div class="table-row header">
+            <div class="cell primary-key">🔑 user_id</div>
+            <div class="cell">name</div>
+            <div class="cell">phone</div>
+            <div class="cell">address</div>
+          </div>
+          <div
+            v-for="user in users"
+            :key="user.user_id"
+            class="table-row"
+            :class="{ highlighted: highlightedUserId === user.user_id }"
+            @mouseenter="highlightedUserId = user.user_id"
+            @mouseleave="highlightedUserId = null"
+          >
+            <div class="cell primary-key">{{ user.user_id }}</div>
+            <div class="cell">{{ user.name }}</div>
+            <div class="cell">{{ user.phone }}</div>
+            <div class="cell">{{ user.address }}</div>
+          </div>
+        </div>
+      </div>
+
+      <div class="relation-arrow">
+        <div class="arrow-line"></div>
+        <div class="arrow-head">➤</div>
+        <div class="relation-label">user_id (外键) → user_id (主键)</div>
+      </div>
+
+      <div class="table-card orders-table">
+        <div class="table-header">
+          <span class="table-icon">📦</span>
+          <span class="table-name">订单表 (orders)</span>
+          <span class="table-badge">从表</span>
+        </div>
+        <div class="table-content">
+          <div class="table-row header">
+            <div class="cell primary-key">🔑 order_id</div>
+            <div class="cell">book_name</div>
+            <div class="cell foreign-key">🔗 user_id</div>
+            <div class="cell">price</div>
+          </div>
+          <div
+            v-for="order in filteredOrders"
+            :key="order.order_id"
+            class="table-row"
+            :class="{ highlighted: highlightedUserId === order.user_id }"
+          >
+            <div class="cell primary-key">{{ order.order_id }}</div>
+            <div class="cell">{{ order.book_name }}</div>
+            <div class="cell foreign-key">{{ order.user_id }}</div>
+            <div class="cell">{{ order.price }}</div>
+          </div>
+        </div>
+      </div>
+    </div>
+
+    <div class="explanation-box">
+      <div class="explanation-title">💡 核心概念</div>
+      <div class="explanation-content">
+        <p><strong>主键（Primary Key）</strong>：用户表的 <code>user_id</code> 是主键，唯一标识每个用户。</p>
+        <p><strong>外键（Foreign Key）</strong>：订单表的 <code>user_id</code> 是外键，指向用户表的主键。</p>
+        <p><strong>关联查询</strong>：通过外键，数据库可以快速找到"订单 001 是用户 101 买的"，然后去用户表查到"用户 101 是张三"。</p>
+      </div>
+    </div>
+
+    <div class="info-box">
+      <span class="icon">🎯</span>
+      <strong>核心优势：</strong>外键消除了数据冗余。张三的地址只存一次，无论他买多少本书。如果要修改地址，只需改用户表的一行，所有订单自动关联到新地址。
     </div>
   </div>
 </template>
 
 <script setup>
-import { ref } from 'vue'
+import { ref, computed } from 'vue'
 
-const title = ref('数据库关系演示')
-const description = ref('展示关系数据库中表与表之间的关系，包括一对一、一对多、多对多关系')
+const highlightedUserId = ref(null)
+
+const users = ref([
+  { user_id: 101, name: '张三', phone: '138xxxx', address: '北京' },
+  { user_id: 102, name: '李四', phone: '139xxxx', address: '上海' },
+  { user_id: 103, name: '王五', phone: '137xxxx', address: '广州' }
+])
+
+const orders = ref([
+  { order_id: '001', book_name: '百年孤独', user_id: 101, price: 59 },
+  { order_id: '002', book_name: '活着', user_id: 101, price: 39 },
+  { order_id: '003', book_name: '三体', user_id: 101, price: 99 },
+  { order_id: '004', book_name: '百年孤独', user_id: 102, price: 59 },
+  { order_id: '005', book_name: '红楼梦', user_id: 102, price: 79 },
+  { order_id: '006', book_name: '西游记', user_id: 103, price: 69 }
+])
+
+const filteredOrders = computed(() => {
+  if (!highlightedUserId.value) {
+    return orders.value
+  }
+  return orders.value.filter(order => order.user_id === highlightedUserId.value)
+})
 </script>
 
 <style scoped>
-.demo-container {
+.relation-demo {
   border: 1px solid var(--vp-c-divider);
   border-radius: 8px;
-  padding: 20px;
   background: var(--vp-c-bg-soft);
+  padding: 1rem;
+  margin: 1rem 0;
 }
 
 .demo-header {
-  margin-bottom: 20px;
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  margin-bottom: 0.75rem;
 }
 
-.demo-header h4 {
-  margin: 0 0 8px 0;
+.demo-header .icon { font-size: 1.25rem; }
+.demo-header .title { font-weight: bold; font-size: 1rem; }
+.demo-header .subtitle { color: var(--vp-c-text-2); font-size: 0.85rem; margin-left: 0.5rem; }
+
+.intro-text {
+  font-size: 0.9rem;
+  color: var(--vp-c-text-2);
+  line-height: 1.6;
+  margin-bottom: 1rem;
+  padding: 0.75rem;
+  background: var(--vp-c-bg);
+  border-radius: 6px;
+}
+
+.intro-text .highlight {
+  color: var(--vp-c-brand-1);
+  font-weight: 500;
+}
+
+.tables-container {
+  display: grid;
+  grid-template-columns: 1fr auto 1fr;
+  gap: 1rem;
+  align-items: start;
+  margin-bottom: 1rem;
+}
+
+@media (max-width: 960px) {
+  .tables-container {
+    grid-template-columns: 1fr;
+  }
+  .relation-arrow {
+    transform: rotate(90deg);
+    margin: 0.5rem 0;
+  }
+}
+
+.table-card {
+  background: var(--vp-c-bg);
+  border-radius: 8px;
+  overflow: hidden;
+  border: 1px solid var(--vp-c-divider);
+}
+
+.table-header {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 0.5rem 0.75rem;
+  background: var(--vp-c-bg-soft);
+  border-bottom: 1px solid var(--vp-c-divider);
+}
+
+.table-icon { font-size: 1rem; }
+.table-name { font-weight: 600; font-size: 0.85rem; flex: 1; }
+.table-badge {
+  font-size: 0.7rem;
+  padding: 2px 6px;
+  border-radius: 4px;
+  background: var(--vp-c-brand-soft);
+  color: var(--vp-c-brand-1);
+}
+
+.table-content {
+  max-height: 280px;
+  overflow-y: auto;
+}
+
+.table-row {
+  display: grid;
+  grid-template-columns: 1fr 1.2fr 1fr 0.8fr;
+  border-bottom: 1px solid var(--vp-c-divider);
+  transition: background 0.2s;
+}
+
+.table-row:last-child {
+  border-bottom: none;
+}
+
+.table.row.header {
+  background: var(--vp-c-bg-soft);
+  font-weight: 600;
+}
+
+.table-row.header .cell {
+  font-size: 0.75rem;
+  color: var(--vp-c-text-2);
+  padding: 0.5rem 0.25rem;
+}
+
+.table-row .cell {
+  font-size: 0.75rem;
+  padding: 0.5rem 0.25rem;
+  color: var(--vp-c-text-1);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.table-row.highlighted {
+  background: rgba(34, 197, 94, 0.1);
+}
+
+.cell.primary-key {
+  color: var(--vp-c-brand-1);
+  font-weight: 500;
+}
+
+.cell.foreign-key {
+  color: #f59e0b;
+  font-weight: 500;
+}
+
+.relation-arrow {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  padding: 1rem 0;
+}
+
+.arrow-line {
+  width: 2px;
+  height: 40px;
+  background: linear-gradient(to right, var(--vp-c-brand), #f59e0b);
+  margin-bottom: 4px;
+}
+
+.arrow-head {
+  color: #f59e0b;
+  font-size: 1.25rem;
+  margin-bottom: 0.5rem;
+}
+
+.relation-label {
+  font-size: 0.65rem;
+  color: var(--vp-c-text-2);
+  text-align: center;
+  max-width: 120px;
+  line-height: 1.3;
+}
+
+.explanation-box {
+  background: var(--vp-c-bg);
+  border-radius: 6px;
+  padding: 0.75rem;
+  margin-bottom: 0.75rem;
+  border: 1px solid var(--vp-c-divider);
+}
+
+.explanation-title {
+  font-size: 0.85rem;
+  font-weight: 600;
+  margin-bottom: 0.5rem;
   color: var(--vp-c-text-1);
 }
 
-.hint {
-  margin: 0;
-  font-size: 14px;
+.explanation-content p {
+  font-size: 0.8rem;
   color: var(--vp-c-text-2);
+  margin: 0.25rem 0;
+  line-height: 1.5;
 }
 
-.demo-content {
-  display: flex;
-  flex-direction: column;
-  gap: 16px;
+.explanation-content code {
+  background: var(--vp-c-bg-soft);
+  padding: 2px 4px;
+  border-radius: 3px;
+  font-family: var(--vp-font-family-mono);
+  font-size: 0.75rem;
+  color: var(--vp-c-brand-1);
 }
+
+.info-box {
+  background: var(--vp-c-bg-alt);
+  padding: 0.75rem;
+  border-radius: 6px;
+  font-size: 0.85rem;
+  color: var(--vp-c-text-2);
+  line-height: 1.5;
+}
+
+.info-box .icon { margin-right: 0.25rem; }
 </style>