chore: add comprehensive documentation and testing infrastructure

## 文档（全部中文）
- AGENTS.md - 完整的 AI 编码指南（中文版）
- CONTRIBUTING.md - 贡献指南
- DEVELOPMENT.md - 开发文档
- DEPLOYMENT.md - 部署文档
- TESTING.md - 测试文档
- TROUBLESHOOTING.md - 问题排查指南
- FAQ.md - 常见问题
- WORKFLOW.md - 标准开发流程文档
## AI 工作流（9个详细工作流）
- feature-development.md - 新功能开发流程
- bug-fix.md - Bug 修复流程
- code-review.md - 代码审查流程
- testing.md - 测试编写流程
- release.md - 发布流程
- refactoring.md - 代码重构流程
- documentation.md - 文档更新流程
- performance-optimization.md - 性能优化流程
- security-audit.md - 安全审计流程
## 测试基础设施
- vitest.config.ts - Vitest 单元测试配置
- playwright.config.ts - Playwright E2E 测试配置
- src/__tests__/setup.ts - 测试环境设置
- src/__tests__/unit/downloadStatus.test.ts - 示例单元测试
- e2e/basic.spec.ts - 示例 E2E 测试
## CI/CD
- .github/workflows/test.yml - 新建测试 CI 工作流
- .github/workflows/build.yml - 更新构建工作流，添加测试步骤
## Issue 模板
- 更新 bug_report.md 为标准 Bug 报告模板
- 更新 help_wanted.md 为标准功能请求模板
## 配置更新
- package.json - 添加测试依赖和 7 个新的 npm 脚本
- .gitignore - 添加测试相关忽略项
## 新增 npm 脚本
- test - 运行单元测试
- test:watch - 监听模式
- test:coverage - 生成覆盖率报告
- test:e2e - 运行 E2E 测试
- test:e2e:ui - E2E UI 模式
- test:e2e:debug - E2E 调试模式
- test:all - 运行所有测试
## 新增测试依赖
- @playwright/test ^1.40.0
- @testing-library/jest-dom ^6.1.5
- @testing-library/vue ^8.0.1
- @vitest/coverage-v8 ^1.0.0
- @vue/test-utils ^2.4.3
- jsdom ^23.0.1
- vitest ^1.0.0

package.json

@@ -30,14 +30,26 @@
     "lint": "eslint --ext .ts,.vue src electron",
     "lint:fix": "eslint --ext .ts,.vue src electron --fix",
     "format": "prettier --write \"src/**/*.{ts,vue}\" \"electron/**/*.{ts,vue}\"",
-    "changelog": "conventional-changelog -p angular -r 0"
+    "changelog": "conventional-changelog -p angular -r 0",
+    "test": "vitest",
+    "test:watch": "vitest --watch",
+    "test:coverage": "vitest --coverage",
+    "test:e2e": "playwright test",
+    "test:e2e:ui": "playwright test --ui",
+    "test:e2e:debug": "playwright test --debug",
+    "test:all": "npm run test && npm run test:e2e"
   },
   "devDependencies": {
     "@dotenvx/dotenvx": "^1.51.4",
     "@eslint/create-config": "^1.11.0",
     "@eslint/js": "^9.39.2",
     "@loongdotjs/electron-builder": "^26.0.12-1",
+    "@playwright/test": "^1.40.0",
+    "@testing-library/jest-dom": "^6.1.5",
+    "@testing-library/vue": "^8.0.1",
     "@vitejs/plugin-vue": "^6.0.3",
+    "@vitest/coverage-v8": "^1.0.0",
+    "@vue/test-utils": "^2.4.3",
     "conventional-changelog": "^7.1.1",
     "conventional-changelog-angular": "^8.1.0",
     "electron": "^40.0.0",
@@ -47,6 +59,7 @@
     "eslint-plugin-vue": "^10.7.0",
     "globals": "^17.3.0",
     "jiti": "^2.6.1",
+    "jsdom": "^23.0.1",
     "pino-pretty": "^13.1.3",
     "prettier": "3.8.1",
     "typescript": "^5.4.2",
@@ -54,6 +67,7 @@
     "vite": "^6.4.1",
     "vite-plugin-electron": "^0.29.0",
     "vite-plugin-electron-renderer": "^0.14.5",
+    "vitest": "^1.0.0",
     "vue": "^3.4.21",
     "vue-tsc": "^3.2.4"
   },