perf(前端): 优化页面加载性能和用户体验

- 添加路由预加载功能，使用 requestIdleCallback 在浏览器空闲时预加载
- 配置 Vite manualChunks 分离 vendor 库（vue/ui/chart/i18n/misc）
- 新增 NavigationProgress 导航进度条组件，支持防闪烁和无障碍
- 集成 Vitest 测试框架，添加 40 个单元测试和集成测试
- 支持 prefers-reduced-motion 和暗色模式

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/package.json

@@ -9,7 +9,10 @@
     "preview": "vite preview",
     "lint": "eslint . --ext .vue,.js,.jsx,.cjs,.mjs,.ts,.tsx,.cts,.mts --fix",
     "lint:check": "eslint . --ext .vue,.js,.jsx,.cjs,.mjs,.ts,.tsx,.cts,.mts",
-    "typecheck": "vue-tsc --noEmit"
+    "typecheck": "vue-tsc --noEmit",
+    "test": "vitest",
+    "test:run": "vitest run",
+    "test:coverage": "vitest run --coverage"
   },
   "dependencies": {
     "@lobehub/icons": "^4.0.2",
@@ -29,17 +32,21 @@
     "@types/file-saver": "^2.0.7",
     "@types/mdx": "^2.0.13",
     "@types/node": "^20.10.5",
-    "@vitejs/plugin-vue": "^5.2.3",
-    "autoprefixer": "^10.4.16",
     "@typescript-eslint/eslint-plugin": "^7.18.0",
     "@typescript-eslint/parser": "^7.18.0",
+    "@vitejs/plugin-vue": "^5.2.3",
+    "@vitest/coverage-v8": "^2.1.9",
+    "@vue/test-utils": "^2.4.6",
+    "autoprefixer": "^10.4.16",
     "eslint": "^8.57.0",
     "eslint-plugin-vue": "^9.25.0",
+    "jsdom": "^24.1.3",
     "postcss": "^8.4.32",
     "tailwindcss": "^3.4.0",
     "typescript": "~5.6.0",
     "vite": "^5.0.10",
     "vite-plugin-checker": "^0.9.1",
+    "vitest": "^2.1.9",
     "vue-tsc": "^2.2.0"
   }
 }