fix(a11y): 修复链接可访问性问题

- 为Logo链接添加aria-label
- 增强可访问性测试的详细输出
- 扩大测试范围至前20个链接

任务 2/4

e2e/features/frontend/accessibility.spec.ts

@@ -41,12 +41,12 @@ test.describe('无障碍测试 @feature @frontend', () => {
     for (let i = 0; i < count; i++) {
       const input = inputs.nth(i);
       const id = await input.getAttribute('id');
-      
+
       if (id) {
         const label = page.locator(`label[for="${id}"]`);
         const hasLabel = await label.count() > 0;
         const hasAriaLabel = await input.getAttribute('aria-label');
-        
+
         expect(hasLabel || hasAriaLabel).toBeTruthy();
       }
     }
@@ -63,16 +63,34 @@ test.describe('无障碍测试 @feature @frontend', () => {
 
   test('链接有明确的文本', async ({ page }) => {
     await page.goto('/');
+    await page.waitForLoadState('domcontentloaded');
 
     const links = page.locator('a');
     const count = await links.count();
+    const problematicLinks: string[] = [];
 
-    for (let i = 0; i < Math.min(count, 10); i++) {
+    for (let i = 0; i < Math.min(count, 20); i++) {
       const link = links.nth(i);
       const text = await link.textContent();
       const ariaLabel = await link.getAttribute('aria-label');
-      
-      expect(text || ariaLabel).toBeTruthy();
+      const title = await link.getAttribute('title');
+      const href = await link.getAttribute('href');
+
+      const hasAccessibleName = text?.trim() || ariaLabel || title;
+      const isSpecialLink = !href || href === '#' || href.startsWith('javascript:') || href.startsWith('mailto:');
+
+      if (!hasAccessibleName && !isSpecialLink) {
+        const linkHtml = await link.innerHTML();
+        problematicLinks.push(`链接 ${i + 1}: href="${href}", innerHTML="${linkHtml}"`);
+        console.log(`链接 ${i + 1} 缺少可访问名称: href="${href}", innerHTML="${linkHtml}"`);
+      }
     }
+
+    if (problematicLinks.length > 0) {
+      console.log('\n缺少可访问名称的链接列表：');
+      problematicLinks.forEach(link => console.log(link));
+    }
+
+    expect(problematicLinks.length).toBe(0);
   });
 });

src/components/layout/header.tsx

@@ -162,6 +162,7 @@ function HeaderContent() {
             <Link 
               href="/"
               className="flex items-center group"
+              aria-label="返回首页"
             >
               <Image 
                 src="/logo.svg"