feat(appendix): 重构工程实践章节，添加交互式演示组件

## 新增组件 (14个)
- CodeSmellDemo.vue: 代码异味识别演示
- DecisionMatrixDemo.vue: 决策矩阵工具
- DesignPatternCatalogDemo.vue: 设计模式目录
- DocStructureDemo.vue: 文档结构示例
- LicenseComparisonDemo.vue: 开源许可证对比
- OpenSourceWorkflowDemo.vue: 开源协作流程
- PatternPlaygroundDemo.vue: 设计模式演练场
- RefactoringDemo.vue: 重构实战演示
- SecurityChecklistDemo.vue: 安全检查清单
- TDDCycleDemo.vue: TDD 循环演示
- TechRadarDemo.vue: 技术雷达图
- TechWritingPracticeDemo.vue: 技术写作实践
- TestPyramidDemo.vue: 测试金字塔
- WebSecurityDemo.vue: Web 安全演示

## 文档更新 (7篇)
- code-quality-refactoring.md: 代码质量与重构
- design-patterns.md: 设计模式
- open-source-collaboration.md: 开源协作
- security-thinking.md: 安全思维
- technical-writing.md: 技术写作
- technology-selection.md: 技术选型
- testing-strategies.md: 测试策略

## 其他变更
- 将 browser-as-os.md 内容合并到 computer-networks.md
- 更新 .gitignore 和 theme/index.js

docs/.vitepress/theme/index.js

@@ -645,6 +645,22 @@ import TypeInferenceDemo from './components/appendix/typescript-intro/TypeInfere
 import SerializationDemo from './components/appendix/server-backend/SerializationDemo.vue'
 import HttpProtocolDemo from './components/appendix/server-backend/HttpProtocolDemo.vue'
 
+// Engineering Excellence Components
+import CodeSmellDemo from './components/appendix/engineering-excellence/CodeSmellDemo.vue'
+import RefactoringDemo from './components/appendix/engineering-excellence/RefactoringDemo.vue'
+import TestPyramidDemo from './components/appendix/engineering-excellence/TestPyramidDemo.vue'
+import TDDCycleDemo from './components/appendix/engineering-excellence/TDDCycleDemo.vue'
+import DesignPatternCatalogDemo from './components/appendix/engineering-excellence/DesignPatternCatalogDemo.vue'
+import PatternPlaygroundDemo from './components/appendix/engineering-excellence/PatternPlaygroundDemo.vue'
+import WebSecurityDemo from './components/appendix/engineering-excellence/WebSecurityDemo.vue'
+import SecurityChecklistDemo from './components/appendix/engineering-excellence/SecurityChecklistDemo.vue'
+import DocStructureDemo from './components/appendix/engineering-excellence/DocStructureDemo.vue'
+import TechWritingPracticeDemo from './components/appendix/engineering-excellence/TechWritingPracticeDemo.vue'
+import OpenSourceWorkflowDemo from './components/appendix/engineering-excellence/OpenSourceWorkflowDemo.vue'
+import LicenseComparisonDemo from './components/appendix/engineering-excellence/LicenseComparisonDemo.vue'
+import TechRadarDemo from './components/appendix/engineering-excellence/TechRadarDemo.vue'
+import DecisionMatrixDemo from './components/appendix/engineering-excellence/DecisionMatrixDemo.vue'
+
 // Data Components
 import SqlDemo from './components/appendix/data/SqlDemo.vue'
 import DataModelsDemo from './components/appendix/data/DataModelsDemo.vue'
@@ -1321,6 +1337,22 @@ export default {
     app.component('ABTestingDemo', ABTestingDemo)
     app.component('DataAnalysisDemo', DataAnalysisDemo)
     app.component('DataTrackingDemo', DataTrackingDemo)
+
+    // Engineering Excellence Components Registration
+    app.component('CodeSmellDemo', CodeSmellDemo)
+    app.component('RefactoringDemo', RefactoringDemo)
+    app.component('TestPyramidDemo', TestPyramidDemo)
+    app.component('TDDCycleDemo', TDDCycleDemo)
+    app.component('DesignPatternCatalogDemo', DesignPatternCatalogDemo)
+    app.component('PatternPlaygroundDemo', PatternPlaygroundDemo)
+    app.component('WebSecurityDemo', WebSecurityDemo)
+    app.component('SecurityChecklistDemo', SecurityChecklistDemo)
+    app.component('DocStructureDemo', DocStructureDemo)
+    app.component('TechWritingPracticeDemo', TechWritingPracticeDemo)
+    app.component('OpenSourceWorkflowDemo', OpenSourceWorkflowDemo)
+    app.component('LicenseComparisonDemo', LicenseComparisonDemo)
+    app.component('TechRadarDemo', TechRadarDemo)
+    app.component('DecisionMatrixDemo', DecisionMatrixDemo)
   },
   setup() {
     const route = useRoute()