feat: add comprehensive backend topics and fix build issues

## 新增内容

### 附录文档扩展
- 扩展前端项目架构文档 (frontend-project-architecture.md)
- 扩展后端项目架构文档 (backend-project-architecture.md)
- 扩展数据治理文档 (data-governance.md)
- 扩展数据可视化文档 (data-visualization.md)
- 扩展分布式系统文档 (distributed-systems.md)
- 扩展高可用文档 (high-availability.md)
- 扩展单体到微服务文档 (monolith-to-microservices.md)
- 扩展系统设计方法论文档 (system-design-methodology.md)
- 扩展 Docker 容器文档 (docker-containers.md)
- 扩展 Kubernetes 文档 (kubernetes.md)
- 扩展 Linux 基础文档 (linux-basics.md)
- 扩展神经网络文档 (neural-networks.md)

### 新增交互式组件
- 数据治理组件: DataQualityDemo, DataGovernanceFrameworkDemo, DataLineageDemo
- 数据可视化组件: ChartTypeSelectorDemo, DashboardLayoutDemo
- 分布式系统组件: CAPTheoremDemo, ConsistencyModelsDemo, DistributedChallengesDemo
- 高可用组件: AvailabilityCalculatorDemo, FailoverStrategyDemo
- 系统设计组件: SystemDesignStepsDemo, CapacityEstimationDemo
- Docker 容器组件: DockerArchitectureDemo, DockerLifecycleDemo
- Kubernetes 组件: K8sArchitectureDemo, K8sWorkloadsDemo
- Linux 基础组件: LinuxFileSystemDemo, LinuxCommandDemo, LinuxPermissionsDemo
- 神经网络组件: NeuronDemo, NetworkLayersDemo, NetworkArchitectureDemo
- 单体到微服务组件: ArchEvolutionDemo
- 项目架构组件: ProjectArchitectureComparisonDemo
- 附录导航组件: AppendixFlowMap

### 英文版重构
- 将 en-us 目录重命名为 en
- 更新相关配置和组件中的语言代码

## Bug 修复
- 修复 index.js 中重复的组件导入语句导致的 build 失败
- 恢复被注释的 InvertedIndexDemo 和 SearchRelevanceDemo 导入
- 修复 HomeFeatures.vue 中 en-us 与 config.mjs 中 en 不一致导致的语言切换问题

## 其他改进
- 添加构建脚本 (scripts/build.mjs)
- 更新依赖版本

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

@@ -418,23 +418,31 @@ onMounted(() => {
   }, 1000)
 })
 
+const blTimer = ref(null)
+const kernelTimer = ref(null)
+const svcTimer = ref(null)
+
 onUnmounted(() => {
   if (timeInterval) clearInterval(timeInterval)
+  if (blTimer.value) clearInterval(blTimer.value)
+  if (kernelTimer.value) clearInterval(kernelTimer.value)
+  if (svcTimer.value) clearInterval(svcTimer.value)
 })
 
 // 引导程序动画
 watch(() => stage.value, (newStage) => {
+  if (blTimer.value) clearInterval(blTimer.value)
   if (newStage === 1) {
     blStep.value = -1
     blCodeLine.value = -1
     let step = 0
-    const interval = setInterval(() => {
+    blTimer.value = setInterval(() => {
       if (step < blSteps.length) {
         blStep.value = step
         blCodeLine.value = step + 1
         step++
       } else {
-        clearInterval(interval)
+        if (blTimer.value) clearInterval(blTimer.value)
       }
     }, 600)
   }
@@ -442,14 +450,15 @@ watch(() => stage.value, (newStage) => {
 
 // 内核加载动画
 watch(() => stage.value, (newStage) => {
+  if (kernelTimer.value) clearInterval(kernelTimer.value)
   if (newStage === 2) {
     kernelProgress.value = 0
     kernelName.value = Math.random() > 0.5 ? 'ntoskrnl.exe' : 'vmlinuz'
-    const interval = setInterval(() => {
+    kernelTimer.value = setInterval(() => {
       if (kernelProgress.value < 100) {
         kernelProgress.value += 4
       } else {
-        clearInterval(interval)
+        if (kernelTimer.value) clearInterval(kernelTimer.value)
       }
     }, 80)
   }
@@ -457,13 +466,14 @@ watch(() => stage.value, (newStage) => {
 
 // 服务启动动画
 watch(() => stage.value, (newStage) => {
+  if (svcTimer.value) clearInterval(svcTimer.value)
   if (newStage === 3) {
     svcProgress.value = 0
-    const interval = setInterval(() => {
+    svcTimer.value = setInterval(() => {
       if (svcProgress.value < 100) {
         svcProgress.value += 3
       } else {
-        clearInterval(interval)
+        if (svcTimer.value) clearInterval(svcTimer.value)
       }
     }, 100)
   }