feat: add SharePanel component for social sharing with QR code support

- Implemented SharePanel component in `SharePanel.astro` for sharing content on social media platforms.
- Integrated QR code generation for WeChat sharing using the `qrcode` library.
- Added localization support for English and Chinese languages.
- Created utility functions in `seo.ts` for building article summaries and FAQs.
- Introduced API routes for serving IndexNow key and generating full LLM catalog and summaries.
- Enhanced SEO capabilities with structured data for articles and pages.

frontend/src/pages/about/index.astro

@@ -1,18 +1,23 @@
 ---
 import BaseLayout from '../../layouts/BaseLayout.astro';
+import DiscoveryBrief from '../../components/seo/DiscoveryBrief.astro';
+import PageViewTracker from '../../components/seo/PageViewTracker.astro';
+import SharePanel from '../../components/seo/SharePanel.astro';
 import TerminalWindow from '../../components/ui/TerminalWindow.astro';
 import CommandPrompt from '../../components/ui/CommandPrompt.astro';
 import StatsList from '../../components/StatsList.astro';
 import TechStackList from '../../components/TechStackList.astro';
 import { api, DEFAULT_SITE_SETTINGS } from '../../lib/api/client';
 import { getI18n } from '../../lib/i18n';
+import { buildDiscoveryHighlights, buildFaqJsonLd, buildPageFaqs } from '../../lib/seo';
 
 export const prerender = false;
 
 let siteSettings = DEFAULT_SITE_SETTINGS;
 let systemStats = [];
 let techStack = [];
-const { t } = getI18n(Astro);
+const { locale, t } = getI18n(Astro);
+const isEnglish = locale.startsWith('en');
 
 try {
   const [settings, posts, tags, friendLinks] = await Promise.all([
@@ -42,13 +47,95 @@ try {
 }
 
 const ownerInitial = siteSettings.ownerName.charAt(0) || 'T';
+const siteBaseUrl = (siteSettings.siteUrl || new URL(Astro.request.url).origin).replace(/\/$/, '');
+const aboutCanonicalUrl = new URL('/about', siteBaseUrl).toString();
+const sharePanelCopy = isEnglish
+  ? {
+      badge: 'profile source',
+      title: 'Share the profile page',
+      description:
+        'Use this page as the canonical identity and capability profile so social sharing and AI search can cite one stable source.',
+    }
+    : {
+      badge: '身份主页',
+      title: '分享这张身份名片页',
+      description: '把这页当成统一的身份与能力来源分发出去，方便社交回流，也方便 AI 搜索引用到同一个规范地址。',
+    };
+const aboutHighlights = buildDiscoveryHighlights([
+  siteSettings.ownerTitle,
+  siteSettings.ownerBio,
+  siteSettings.location || '',
+  siteSettings.techStack.slice(0, 4).join(' / '),
+]);
+const aboutFaqs = buildPageFaqs({
+  locale,
+  pageTitle: t('about.pageTitle'),
+  summary: siteSettings.ownerBio || siteSettings.siteDescription,
+  primaryLabel: t('about.pageTitle'),
+  primaryUrl: aboutCanonicalUrl,
+  relatedLinks: [
+    { label: t('nav.articles'), url: `${siteBaseUrl}/articles` },
+    { label: t('nav.timeline'), url: `${siteBaseUrl}/timeline` },
+    { label: t('nav.ask'), url: `${siteBaseUrl}/ask` },
+  ],
+  signals: aboutHighlights,
+});
+const aboutFaqJsonLd = buildFaqJsonLd(aboutFaqs);
+const aboutJsonLd = [
+  {
+    '@context': 'https://schema.org',
+    '@type': 'AboutPage',
+    name: `${siteSettings.ownerName} / ${siteSettings.siteName}`,
+    description: siteSettings.siteDescription,
+    url: aboutCanonicalUrl,
+    inLanguage: locale,
+  },
+  {
+    '@context': 'https://schema.org',
+    '@type': 'ProfilePage',
+    name: siteSettings.ownerName,
+    url: aboutCanonicalUrl,
+    mainEntity: {
+      '@type': 'Person',
+      name: siteSettings.ownerName,
+      jobTitle: siteSettings.ownerTitle,
+      description: siteSettings.ownerBio,
+      image: siteSettings.ownerAvatarUrl || undefined,
+      sameAs: [
+        siteSettings.social.github,
+        siteSettings.social.twitter,
+      ].filter(Boolean),
+    },
+  },
+  {
+    '@context': 'https://schema.org',
+    '@type': 'BreadcrumbList',
+    itemListElement: [
+      {
+        '@type': 'ListItem',
+        position: 1,
+        name: siteSettings.siteName,
+        item: siteBaseUrl,
+      },
+      {
+        '@type': 'ListItem',
+        position: 2,
+        name: t('about.pageTitle'),
+        item: aboutCanonicalUrl,
+      },
+    ],
+  },
+  aboutFaqJsonLd,
+];
 ---
 
 <BaseLayout
   title={`${t('about.pageTitle')} - ${siteSettings.siteShortName}`}
   description={siteSettings.siteDescription}
   siteSettings={siteSettings}
+  jsonLd={aboutJsonLd.filter(Boolean)}
 >
+  <PageViewTracker pageType="about" entityId="about" />
   <div class="max-w-5xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
     <TerminalWindow title="~/about" class="w-full">
       <div class="mb-6 px-4">
@@ -77,6 +164,31 @@ const ownerInitial = siteSettings.ownerName.charAt(0) || 'T';
             </span>
           </div>
         </div>
+
+        <div class="ml-4 mt-4">
+          <SharePanel
+            shareTitle={`${siteSettings.ownerName} / ${t('about.pageTitle')}`}
+            summary={siteSettings.ownerBio || siteSettings.siteDescription}
+            canonicalUrl={aboutCanonicalUrl}
+            badge={sharePanelCopy.badge}
+            kicker="geo / profile"
+            title={sharePanelCopy.title}
+            description={sharePanelCopy.description}
+            stats={systemStats.slice(0, 4)}
+            wechatShareQrEnabled={siteSettings.seo.wechatShareQrEnabled}
+          />
+        </div>
+
+        <div class="ml-4 mt-4">
+          <DiscoveryBrief
+            badge={isEnglish ? 'profile brief' : '身份摘要'}
+            kicker="geo / profile"
+            title={isEnglish ? 'AI-readable profile brief' : '给 AI 看的身份摘要'}
+            summary={siteSettings.ownerBio || siteSettings.siteDescription}
+            highlights={aboutHighlights}
+            faqs={aboutFaqs}
+          />
+        </div>
       </div>
 
       <div class="px-4">