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/site-doc/SiteDocPageNav.tsx

@@ -2,10 +2,12 @@ import Link from "next/link";
 import { ChevronRight } from "lucide-react";
 import type { SidebarPageItem } from "@/lib/api";
 import { pageGlyph } from "@/lib/pageGlyph";
+import { getPublicSettingsCached } from "@/lib/serverData";
+import { pagePath } from "@/lib/urlStyle";
 import AboutSiteHeader from "./AboutSiteHeader";
 
 /** 侧栏单页兄弟目录（高亮当前 slug）；标题栏与首页「关于本站」一致 */
-export default function SiteDocPageNav({
+export default async function SiteDocPageNav({
   pages,
   currentSlug,
   title = "文档目录",
@@ -17,6 +19,7 @@ export default function SiteDocPageNav({
   canManage?: boolean;
 }) {
   if (pages.length === 0 && !canManage) return null;
+  const urlStyle = (await getPublicSettingsCached()).url_style;
 
   return (
     <section className="j13-module j13-about flex min-h-0 flex-col" aria-label={title}>
@@ -31,7 +34,7 @@ export default function SiteDocPageNav({
             return (
               <li key={p.id}>
                 <Link
-                  href={`/p/${p.slug}`}
+                  href={pagePath(urlStyle, p.slug)}
                   className="j13-about-item"
                   aria-current={current ? "page" : undefined}
                   style={