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.

deploy/docker/.env.example

@@ -18,6 +18,10 @@ PUBLIC_API_BASE_URL=
 # PUBLIC_IMAGE_ALLOWED_HOSTS=cdn.example.com,pub-xxxx.r2.dev
 PUBLIC_IMAGE_ALLOWED_HOSTS=
 
+# 如果你要启用 IndexNow 自动提交，请填写一个你自己的 key。
+# frontend 会在 /indexnow-key.txt 暴露这个 key，配合 `pnpm indexnow:submit` 使用。
+INDEXNOW_KEY=
+
 # admin 浏览器请求 backend API 优先读取这个公开地址。
 # 如果留空，admin 会在生产环境按“当前访问主机 + :5150”回退。
 # 如果你采用推荐方案（admin 域名同域转发 /api 到 backend），

deploy/docker/compose.package.yml

@@ -68,6 +68,7 @@ services:
       PUBLIC_COMMENT_TURNSTILE_SITE_KEY: ${PUBLIC_COMMENT_TURNSTILE_SITE_KEY:-}
       PUBLIC_WEB_PUSH_VAPID_PUBLIC_KEY: ${PUBLIC_WEB_PUSH_VAPID_PUBLIC_KEY:-}
       PUBLIC_IMAGE_ALLOWED_HOSTS: ${PUBLIC_IMAGE_ALLOWED_HOSTS:-}
+      INDEXNOW_KEY: ${INDEXNOW_KEY:-}
     # frontend 是 Astro SSR(Node) 服务，容器内部监听 4321
     # 生产建议由网关统一反代，仅对外开放 80/443
     ports: