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/QueryOptimizationDemo.vue

@@ -1,13 +1,63 @@
 <template>
-  <div class="demo-container">
+  <div class="optimization-demo">
     <div class="demo-header">
-      <h4>{{ title }}</h4>
-      <p class="hint">{{ description }}</p>
+      <span class="icon">⚡</span>
+      <span class="title">查询优化演示</span>
+      <span class="subtitle">常见错误与正确做法对比</span>
     </div>
-    <div class="demo-content">
-      <el-alert type="info" :closable="false">
-        查询优化演示组件占位符 - 待实现具体交互
-      </el-alert>
+
+    <div class="intro-text">
+      很多时候，查询慢不是因为<span class="highlight">数据库性能差</span>，而是因为 SQL 写错了。下面这些错误，你可能每天都在犯。
+    </div>
+
+    <div class="pitfalls-list">
+      <div
+        v-for="(pitfall, index) in pitfalls"
+        :key="index"
+        class="pitfall-card"
+        :class="{ expanded: expandedIndex === index }"
+      >
+        <div class="pitfall-header" @click="expandedIndex = expandedIndex === index ? null : index">
+          <div class="pitfall-number">{{ index + 1 }}</div>
+          <div class="pitfall-title">{{ pitfall.title }}</div>
+          <div class="expand-icon">{{ expandedIndex === index ? '▼' : '▶' }}</div>
+        </div>
+
+        <Transition name="expand">
+          <div v-if="expandedIndex === index" class="pitfall-content">
+            <div class="code-comparison">
+              <div class="code-section wrong">
+                <div class="section-label">❌ 错误写法</div>
+                <pre><code>{{ pitfall.wrong }}</code></pre>
+                <div class="impact">⚠️ {{ pitfall.impact }}</div>
+              </div>
+              <div class="code-section correct">
+                <div class="section-label">✅ 正确写法</div>
+                <pre><code>{{ pitfall.correct }}</code></pre>
+                <div class="benefit">💡 {{ pitfall.benefit }}</div>
+              </div>
+            </div>
+            <div class="explanation">
+              <strong>原理：</strong>{{ pitfall.explanation }}
+            </div>
+          </div>
+        </Transition>
+      </div>
+    </div>
+
+    <div class="tips-box">
+      <div class="tips-title">📝 优化建议清单</div>
+      <div class="tips-list">
+        <div v-for="(tip, i) in tips" :key="i" class="tip-item">
+          <span class="tip-icon">✓</span>
+          <span class="tip-text">{{ tip }}</span>
+        </div>
+      </div>
+    </div>
+
+    <div class="info-box">
+      <span class="icon">🎯</span>
+      <strong>核心原则：</strong>不要让数据库做"多余的工作"。索引失效、全表扫描、返回不必要的数据，这些都是最常见的性能杀手。写出高效 SQL 的关键，是<span class="highlight">理解数据库如何执行你的查询</span>。
     </div>
   </div>
 </template>
@@ -15,36 +65,301 @@
 <script setup>
 import { ref } from 'vue'
 
-const title = ref('查询优化演示')
-const description = ref('展示数据库查询优化的原理和方法，包括执行计划分析和索引优化')
+const expandedIndex = ref(0)
+
+const pitfalls = ref([
+  {
+    title: '在索引列上使用函数',
+    wrong: "SELECT * FROM users WHERE YEAR(created_at) = 2024;",
+    correct: "SELECT * FROM users WHERE created_at >= '2024-01-01' AND created_at < '2025-01-01';",
+    impact: '索引失效，全表扫描',
+    benefit: '可以使用索引，查询速度提升 1000 倍',
+    explanation: '当对列使用函数时，数据库必须先计算每一行的函数值，无法使用索引。把函数移到等号右边，或用范围查询代替。'
+  },
+  {
+    title: '隐式类型转换',
+    wrong: "SELECT * FROM users WHERE user_id = '123';  -- user_id 是 int",
+    correct: "SELECT * FROM users WHERE user_id = 123;",
+    impact: '索引失效，每次都要类型转换',
+    benefit: '直接使用索引',
+    explanation: '字符串和数字比较时，数据库会隐式转换，导致索引失效。确保比较的类型和列定义的类型一致。'
+  },
+  {
+    title: 'LIKE 以 % 开头',
+    wrong: "SELECT * FROM users WHERE name LIKE '%张三%';",
+    correct: "SELECT * FROM users WHERE name LIKE '张三%';",
+    impact: '无法使用索引，全表扫描',
+    benefit: '可以使用索引进行前缀匹配',
+    explanation: '索引是按照顺序存储的，% 开头的模糊查询无法利用顺序。如果只需要前缀匹配，把 % 放到后面。'
+  },
+  {
+    title: 'SELECT * 返回所有列',
+    wrong: "SELECT * FROM users WHERE user_id = 1;",
+    correct: "SELECT user_id, name, email FROM users WHERE user_id = 1;",
+    impact: '增加网络传输和内存消耗，无法使用覆盖索引',
+    benefit: '减少传输量，可能使用覆盖索引',
+    explanation: '只查询需要的列。如果索引包含了所有需要的列，数据库可以直接从索引返回数据，不需要查表（覆盖索引）。'
+  }
+])
+
+const tips = ref([
+  '为 WHERE、JOIN、ORDER BY 的列创建索引',
+  '避免在索引列上使用函数或表达式',
+  '用 EXPLAIN 分析查询执行计划',
+  '只查询需要的列，避免 SELECT *',
+  '批量操作代替单条操作',
+  '考虑使用覆盖索引减少回表'
+])
 </script>
 
 <style scoped>
-.demo-container {
+.optimization-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;
+}
+
+.pitfalls-list {
+  display: flex;
+  flex-direction: column;
+  gap: 0.75rem;
+  margin-bottom: 1rem;
+}
+
+.pitfall-card {
+  background: var(--vp-c-bg);
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 6px;
+  overflow: hidden;
+}
+
+.pitfall-header {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+  padding: 0.75rem;
+  cursor: pointer;
+  transition: background 0.2s;
+}
+
+.pitfall-header:hover {
+  background: var(--vp-c-bg-soft);
+}
+
+.pitfall-number {
+  width: 24px;
+  height: 24px;
+  background: var(--vp-c-brand);
+  color: white;
+  border-radius: 50%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 0.75rem;
+  font-weight: 600;
+  flex-shrink: 0;
+}
+
+.pitfall-title {
+  flex: 1;
+  font-size: 0.85rem;
+  font-weight: 500;
   color: var(--vp-c-text-1);
 }
 
-.hint {
+.expand-icon {
+  font-size: 0.65rem;
+  color: var(--vp-c-text-3);
+  flex-shrink: 0;
+}
+
+.pitfall-content {
+  padding: 0 0.75rem 0.75rem;
+}
+
+.code-comparison {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 0.75rem;
+  margin-bottom: 0.75rem;
+}
+
+@media (max-width: 768px) {
+  .code-comparison {
+    grid-template-columns: 1fr;
+  }
+}
+
+.code-section {
+  border-radius: 6px;
+  overflow: hidden;
+}
+
+.code-section.wrong {
+  background: rgba(239, 68, 68, 0.05);
+  border: 1px solid rgba(239, 68, 68, 0.2);
+}
+
+.code-section.correct {
+  background: rgba(34, 197, 94, 0.05);
+  border: 1px solid rgba(34, 197, 94, 0.2);
+}
+
+.section-label {
+  padding: 0.5rem 0.75rem;
+  font-size: 0.75rem;
+  font-weight: 600;
+}
+
+.code-section.wrong .section-label {
+  color: #ef4444;
+  background: rgba(239, 68, 68, 0.1);
+}
+
+.code-section.correct .section-label {
+  color: #22c55e;
+  background: rgba(34, 197, 94, 0.1);
+}
+
+.code-section pre {
   margin: 0;
-  font-size: 14px;
+  padding: 0.75rem;
+  overflow-x: auto;
+  background: rgba(0, 0, 0, 0.02);
+}
+
+.code-section code {
+  font-family: var(--vp-font-family-mono);
+  font-size: 0.7rem;
+  line-height: 1.5;
+  color: var(--vp-c-brand-1);
+}
+
+.impact, .benefit {
+  padding: 0.5rem 0.75rem;
+  font-size: 0.75rem;
+}
+
+.impact {
+  color: #ef4444;
+  background: rgba(239, 68, 68, 0.1);
+}
+
+.benefit {
+  color: #22c55e;
+  background: rgba(34, 197, 94, 0.1);
+}
+
+.explanation {
+  font-size: 0.8rem;
+  color: var(--vp-c-text-2);
+  line-height: 1.5;
+}
+
+.tips-box {
+  background: var(--vp-c-bg);
+  border-radius: 6px;
+  padding: 0.75rem;
+  margin-bottom: 0.75rem;
+  border: 1px solid var(--vp-c-divider);
+}
+
+.tips-title {
+  font-size: 0.85rem;
+  font-weight: 600;
+  margin-bottom: 0.5rem;
+  color: var(--vp-c-text-1);
+}
+
+.tips-list {
+  display: grid;
+  grid-template-columns: repeat(2, 1fr);
+  gap: 0.5rem;
+}
+
+@media (max-width: 640px) {
+  .tips-list {
+    grid-template-columns: 1fr;
+  }
+}
+
+.tip-item {
+  display: flex;
+  align-items: baseline;
+  gap: 0.5rem;
+  font-size: 0.8rem;
   color: var(--vp-c-text-2);
 }
 
-.demo-content {
-  display: flex;
-  flex-direction: column;
-  gap: 16px;
+.tip-icon {
+  color: #22c55e;
+  font-weight: bold;
+  flex-shrink: 0;
+}
+
+.tip-text {
+  line-height: 1.4;
+}
+
+.expand-enter-active,
+.expand-leave-active {
+  transition: all 0.3s ease;
+  overflow: hidden;
+}
+
+.expand-enter-from,
+.expand-leave-to {
+  max-height: 0;
+  opacity: 0;
+}
+
+.expand-enter-to,
+.expand-leave-from {
+  max-height: 1000px;
+  opacity: 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; }
+
+.info-box .highlight {
+  color: var(--vp-c-brand-1);
+  font-weight: 500;
 }
 </style>