feat(admin): 独立后台壳、站点分析与聊天监管，公开站拆出主题切换与访问埋点

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

frontend/components/markdown/MdLink.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import type { AnchorHTMLAttributes } from "react";
+import { usePostLinkNewTab } from "@/components/PostLinkProvider";
 
 type MdLinkProps = AnchorHTMLAttributes<HTMLAnchorElement>;
 
@@ -21,14 +22,15 @@ function isExternalHref(href?: string): boolean {
   return /^https?:\/\//i.test(href);
 }
 
-/** Markdown 链接：外链新开页 */
+/** Markdown 链接：外链是否新开由站点设置 post_link_new_tab 控制 */
 export default function MdLink({ href, children, ...rest }: MdLinkProps) {
+  const openInNewTab = usePostLinkNewTab();
   const external = isExternalHref(href);
   return (
     <a
       {...rest}
       href={href}
-      {...(external
+      {...(external && openInNewTab
         ? { target: "_blank", rel: "noopener noreferrer" }
         : {})}
     >