fix: 单页正文改用 post-detail-content 对齐帖子排版

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/pages/SitePageView.tsx

@@ -8,12 +8,14 @@ import PageLoader from '../components/PageLoader';
 import { usePageSEO } from '../hooks/usePageSEO';
 import { parsePermalinkSlug, pagePath } from '../utils/permalink';
 import { useForumLimits } from '../hooks/useForumLimits';
+import { useAuth } from '../hooks/useAuth';
 
 /** 自定义单页（关于我们、版规等） */
 export default function SitePageView() {
   const { slug: rawSlug } = useParams();
   const slug = parsePermalinkSlug(rawSlug);
   const { limits } = useForumLimits();
+  const { user } = useAuth();
   const [page, setPage] = useState<SitePage | null>(null);
   const [loading, setLoading] = useState(true);
   const [notFound, setNotFound] = useState(false);
@@ -48,7 +50,11 @@ export default function SitePageView() {
         <header className="site-page__head">
           <h1>{page.title}</h1>
         </header>
-        <PostContent html={page.content} className="site-page__body post-body" />
+        <PostContent
+          html={page.content}
+          isLoggedIn={!!user}
+          className="site-page__body post-detail-content"
+        />
       </article>
     </div>
   );