feat: 增加测试覆盖率并优化代码质量

test: 添加单元测试和端到端测试
refactor: 重构登录页面和上传模块
ci: 更新测试覆盖率阈值至42%
build: 添加测试相关依赖
docs: 更新测试文档
style: 修复代码格式问题

e2e/playwright.coverage.config.ts

@@ -0,0 +1,25 @@
+import { defineConfig, devices } from '@playwright/test';
+
+export default defineConfig({
+  testDir: './src/tests',
+  fullyParallel: true,
+  forbidOnly: !!process.env.CI,
+  retries: 0,
+  timeout: 30000,
+  use: {
+    baseURL: 'http://localhost:3000',
+    trace: 'off',
+    screenshot: 'off',
+    video: 'off',
+    headless: true,
+    viewport: { width: 1280, height: 720 },
+    actionTimeout: 15000,
+    navigationTimeout: 30000,
+  },
+  projects: [
+    {
+      name: 'chromium',
+      use: { ...devices['Desktop Chrome'] },
+    },
+  ],
+});