feat: update AppRouter with layout routes, add Docs and Blog pages

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/pages/DocsListPage.tsx

@@ -0,0 +1,27 @@
+import { Link } from 'react-router-dom';
+import SEOHead from '../components/seo/SEOHead';
+import { useLanguage } from '../contexts/LanguageContext';
+
+const docs = [
+  { slug: 'getting-started', title: 'Getting Started', titleZh: '快速开始', description: 'Learn how to use TexPixel for formula recognition', descriptionZh: '了解如何使用 TexPixel 进行公式识别' },
+];
+
+export default function DocsListPage() {
+  const { language } = useLanguage();
+  return (
+    <>
+      <SEOHead title="Documentation" description="TexPixel documentation and guides" path="/docs" />
+      <div className="max-w-4xl mx-auto py-16 px-6">
+        <h1 className="text-3xl font-bold text-gray-900 mb-8">{language === 'en' ? 'Documentation' : '文档'}</h1>
+        <div className="space-y-4">
+          {docs.map((doc) => (
+            <Link key={doc.slug} to={`/docs/${doc.slug}`} className="block p-6 bg-gray-50 rounded-lg hover:bg-gray-100 transition-colors">
+              <h2 className="text-lg font-semibold text-gray-900">{language === 'en' ? doc.title : doc.titleZh}</h2>
+              <p className="text-gray-600 mt-1 text-sm">{language === 'en' ? doc.description : doc.descriptionZh}</p>
+            </Link>
+          ))}
+        </div>
+      </div>
+    </>
+  );
+}