feat: 提升测试覆盖率并优化测试用例

新增测试:
- use-page-views.test.ts: 测试页面浏览跟踪功能
- api-response.test.ts: 测试API响应辅助函数
- analytics.test.ts: 优化分析函数测试

覆盖率提升:
- branches: 40% -> 41.62%
- functions: 45% -> 47.3%
- lines: 50% -> 52.82%
- statements: 50% -> 51.82%

更新覆盖率阈值到当前水平

config/test/jest.config.js

@@ -11,10 +11,10 @@ module.exports = {
   ],
   coverageThreshold: {
     global: {
-      branches: 40,
-      functions: 45,
-      lines: 50,
-      statements: 50,
+      branches: 41,
+      functions: 47,
+      lines: 52,
+      statements: 51,
     },
   },
   coverageReporters: ['text', 'lcov', 'html', 'json'],