feat: 可配置站点 URL 风格

- 新增 urlStyle 工具与测试：postPath/userPath/sitePagePath 统一生成链接
- 管理端新增 UrlStylePanel 设置面板，settings 服务与 handler 适配
- 全站路由链接与 JSON-LD/sitemap 切换为统一 URL 生成
- middleware 与相关组件适配

frontend/components/NotificationBell.tsx

@@ -13,9 +13,12 @@ import {
 } from "@/lib/api";
 import { realtime, RT_NOTIFICATION_NEW } from "@/lib/realtime";
 import { onDocumentVisible } from "@/lib/visibilityReconcile";
+import { useUrlStyle } from "@/components/SiteBrandProvider";
+import { postPath, userPath } from "@/lib/urlStyle";
 
 export default function NotificationBell({ initialUnread = 0 }: { initialUnread?: number }) {
   const router = useRouter();
+  const urlStyle = useUrlStyle();
   const [open, setOpen] = useState(false);
   // SSR 直出未读数，红点不再挂载后才弹出；WS/回前台校准
   const [unread, setUnread] = useState(initialUnread);
@@ -103,16 +106,16 @@ export default function NotificationBell({ initialUnread = 0 }: { initialUnread?
     if (n.type === "mention" && n.room_id) {
       router.push(`/chat/${n.room_id}`);
     } else if (n.type === "pending_review") {
-      router.push(n.post_id ? `/post/${n.post_id}` : "/admin/content?status=pending");
+      router.push(n.post_id ? postPath(urlStyle, n.post_id) : "/admin/content?status=pending");
     } else if (n.type === "badge") {
       return;
     } else if (n.type === "follow") {
-      router.push(`/u/${n.actor_id}`);
+      router.push(userPath(urlStyle, n.actor_id));
     } else if (n.comment_id > 0) {
       // 评论/回复/点赞等：直达评论所在楼层（跨页由帖子页深链定位换页）
-      router.push(`/post/${n.post_id}#comment-${n.comment_id}`);
+      router.push(`${postPath(urlStyle, n.post_id)}#comment-${n.comment_id}`);
     } else {
-      router.push(`/post/${n.post_id}`);
+      router.push(postPath(urlStyle, n.post_id));
     }
   };