feat(appendix): 添加多个交互式演示组件，完善 AI/Infra 等章节内容

- 新增 Vibe Coding 全栈相关演示组件 (DeveloperSkillShift, FrontendTriad, BackendCore 等)
- 新增 RAG 相关组件 (RAGPipeline, ChunkingStrategy, Retrieval 等)
- 新增 Embedding & Vector 相关组件 (EmbeddingConcept, VectorSimilarity 等)
- 新增 AI Native App 设计组件 (AINativeArch, PromptDesign 等)
- 新增 Infrastructure as Code 组件 (IaCConcept, TerraformWorkflow 等)
- 新增 DNS & HTTPS 演示组件 (DnsResolution, HttpsHandshake 等)
- 新增 Model Finetuning 组件 (FinetuningPipeline 等)
- 更新多个章节的 markdown 内容，集成交互式演示

docs/.vitepress/theme/components/appendix/computer-fundamentals/ComputerFieldMapDemo.vue

@@ -0,0 +1,164 @@
+<template>
+  <div class="field-map-demo">
+    <div class="demo-header">
+      <span class="title">计算机领域全景图</span>
+      <span class="subtitle">点击查看详情</span>
+    </div>
+
+    <div class="field-grid">
+      <div
+        v-for="field in fields"
+        :key="field.name"
+        class="field-card"
+        :class="{ active: activeField === field.name }"
+        @click="activeField = field.name"
+      >
+        <div class="field-name">{{ field.name }}</div>
+        <div class="field-desc">{{ field.desc }}</div>
+        <div class="field-techs">
+          <span v-for="tech in field.techs" :key="tech" class="tech-tag">{{ tech }}</span>
+        </div>
+      </div>
+    </div>
+
+    <div class="info-box">
+      <strong>建议：</strong>不要试图一次学完所有方向。先选一个方向深入，建立"根据地"，再横向扩展。
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+
+const activeField = ref('前端')
+
+const fields = ref([
+  {
+    name: '前端',
+    desc: '用户能看到、能交互的一切',
+    techs: ['HTML/CSS', 'JavaScript', 'React/Vue']
+  },
+  {
+    name: '后端',
+    desc: '服务器端的业务逻辑和数据处理',
+    techs: ['Node.js', 'Go', 'Java', 'Python']
+  },
+  {
+    name: '移动端',
+    desc: '手机上的应用体验',
+    techs: ['Swift', 'Kotlin', 'Flutter']
+  },
+  {
+    name: 'AI/算法',
+    desc: '让系统变"聪明"',
+    techs: ['PyTorch', 'TensorFlow', '机器学习']
+  },
+  {
+    name: '运维/DevOps',
+    desc: '保证系统稳定运行',
+    techs: ['Docker', 'K8s', 'CI/CD']
+  },
+  {
+    name: '数据工程',
+    desc: '数据采集、存储、分析',
+    techs: ['SQL', 'Spark', '数据仓库']
+  }
+])
+</script>
+
+<style scoped>
+.field-map-demo {
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 8px;
+  background: var(--vp-c-bg-soft);
+  padding: 1rem 1.2rem;
+  margin: 1rem 0;
+}
+
+.demo-header {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+  margin-bottom: 1rem;
+  padding-bottom: 0.75rem;
+  border-bottom: 1px solid var(--vp-c-divider);
+}
+
+.title {
+  font-size: 0.95rem;
+  font-weight: 600;
+  color: var(--vp-c-text-1);
+}
+
+.subtitle {
+  font-size: 0.78rem;
+  color: var(--vp-c-text-3);
+}
+
+.field-grid {
+  display: grid;
+  grid-template-columns: repeat(3, 1fr);
+  gap: 0.75rem;
+}
+
+.field-card {
+  padding: 0.75rem;
+  background: var(--vp-c-bg);
+  border: 1px solid var(--vp-c-divider);
+  border-radius: 6px;
+  cursor: pointer;
+  transition: all 0.2s ease;
+}
+
+.field-card:hover {
+  border-color: var(--vp-c-brand-1);
+}
+
+.field-card.active {
+  border-color: var(--vp-c-brand-1);
+  background: var(--vp-c-bg-soft);
+}
+
+.field-name {
+  font-size: 0.85rem;
+  font-weight: 600;
+  color: var(--vp-c-text-1);
+  margin-bottom: 0.25rem;
+}
+
+.field-desc {
+  font-size: 0.72rem;
+  color: var(--vp-c-text-3);
+  margin-bottom: 0.5rem;
+}
+
+.field-techs {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.25rem;
+}
+
+.tech-tag {
+  font-size: 0.68rem;
+  padding: 0.15rem 0.4rem;
+  background: var(--vp-c-bg-soft);
+  border-radius: 3px;
+  color: var(--vp-c-text-2);
+}
+
+.info-box {
+  margin-top: 1rem;
+  padding: 0.75rem;
+  background: var(--vp-c-bg);
+  border-radius: 6px;
+  font-size: 0.8rem;
+  color: var(--vp-c-text-2);
+  border-left: 3px solid var(--vp-c-brand-1);
+}
+
+@media (max-width: 640px) {
+  .field-grid {
+    grid-template-columns: repeat(2, 1fr);
+  }
+}
+</style>