feat(admin): 完善站点设置、内容回收站与后台菜单分组

新增站点设置与内容管理（含已删除恢复/清除），用户页改用独有运营指标，并按概览/内容/成员与经济/站点重组侧栏。

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

frontend/components/Header.tsx

@@ -36,11 +36,15 @@ export default function Header({
   initialUnread = 0,
   initialChatUnread = 0,
   initialTheme = "light",
+  siteName = "姜十三",
+  allowRegister = true,
 }: {
   initialUser: User | null;
   initialUnread?: number;
   initialChatUnread?: number;
   initialTheme?: "light" | "dark";
+  siteName?: string;
+  allowRegister?: boolean;
 }) {
   const router = useRouter();
   const pathname = usePathname();
@@ -226,7 +230,7 @@ export default function Header({
             </span>
             <span className="leading-none">
               <span className="block font-extrabold text-[17px] tracking-tight" style={{ color: "var(--ink)" }}>
-                姜十三
+                {siteName}
               </span>
               <span className="block text-[10.5px] mt-0.5" style={{ color: "var(--ink-3)" }}>
                 J13 社区
@@ -332,9 +336,11 @@ export default function Header({
               <Link href="/login" className="btn btn-line btn-sm">
                 <LogIn size={14} /> 登录
               </Link>
-              <Link href="/register" className="btn btn-primary btn-sm">
-                <UserPlus size={14} /> 注册
-              </Link>
+              {allowRegister && (
+                <Link href="/register" className="btn btn-primary btn-sm">
+                  <UserPlus size={14} /> 注册
+                </Link>
+              )}
             </div>
           )}
           <button
@@ -398,7 +404,7 @@ export default function Header({
               </MobileLink>
             )}
             {!user && <MobileLink href="/login">登录</MobileLink>}
-            {!user && <MobileLink href="/register">注册</MobileLink>}
+            {!user && allowRegister && <MobileLink href="/register">注册</MobileLink>}
           </div>
           <div className="pt-3 mt-2 border-t flex items-center justify-between" style={{ borderColor: "var(--line)" }}>
             <button onClick={toggleTheme} className="btn btn-line btn-sm">