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/app/admin/content/ContentAdmin.tsx

@@ -42,9 +42,11 @@ import {
 } from "@/lib/api";
 import { canModerateAuthor } from "@/lib/roles";
 import { formatRelative } from "@/lib/format";
+import { postPath } from "@/lib/urlStyle";
 import { toast } from "@/lib/toast";
 import { realtime, RT_MODERATION_CHANGED } from "@/lib/realtime";
 import Avatar from "@/components/Avatar";
+import { useUrlStyle } from "@/components/SiteBrandProvider";
 import AutolinkText from "@/components/AutolinkText";
 import ConfirmDialog from "@/components/ConfirmDialog";
 import StaffDeletePostModal from "@/components/StaffDeletePostModal";
@@ -278,6 +280,7 @@ export default function ContentAdmin({
   canPurge: boolean;
   viewerRole: string;
 }) {
+  const urlStyle = useUrlStyle();
   // 窄屏分段：lg 以下只显示一栏；PC 双栏同时可见
   const [mobileKind, setMobileKind] = useState<ContentKind>(initialKind);
   const [counts, setCounts] = useState(initialCounts);
@@ -549,7 +552,7 @@ export default function ContentAdmin({
                   </p>
                 ) : (
                   <Link
-                    href={`/post/${p.id}`}
+                    href={postPath(urlStyle, p.id)}
                     className="mt-1 block text-[13px] font-medium leading-snug hover:underline line-clamp-2"
                     style={{ color: "var(--ink)" }}
                     data-tip={p.title}
@@ -689,7 +692,7 @@ export default function ContentAdmin({
                     c.post_title
                   ) : (
                     <Link
-                      href={`/post/${c.post_id}#comment-${c.id}`}
+                      href={`${postPath(urlStyle, c.post_id)}#comment-${c.id}`}
                       className="hover:underline"
                       style={{ color: "var(--accent)" }}
                     >