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/app/admin/AdminNav.tsx

@@ -13,6 +13,8 @@ import {
   ArrowLeft,
   ClipboardCheck,
   Coins,
+  Globe,
+  FolderOpen,
 } from "lucide-react";
 import type { User } from "@/lib/api";
 import { apiAdminPendingCounts } from "@/lib/api";
@@ -32,45 +34,80 @@ interface NavItem {
   label: string;
   icon: LucideIcon;
   exact?: boolean;
-  /** 按 /me 角色过滤可见性；最终权限以后端路由守卫为准 */
   visible: (u: RoleUserLike) => boolean;
-  /** 是否携带待审核角标 */
   pendingBadge?: boolean;
 }
 
-// 后台导航项：exact 为精确匹配（仪表盘 /admin），其余按路径前缀匹配
-const NAV_ITEMS: NavItem[] = [
-  { href: "/admin", label: "仪表盘", icon: LayoutDashboard, exact: true, visible: () => true },
+interface NavGroup {
+  title: string;
+  items: NavItem[];
+}
+
+// 分组导航：概览 → 内容运营 → 成员经济 → 站点配置，便于后期在组内扩展
+const NAV_GROUPS: NavGroup[] = [
   {
-    href: "/admin/moderation",
-    label: "内容审核",
-    icon: ClipboardCheck,
-    visible: (u) => canModerateAny(u),
-    pendingBadge: true,
+    title: "概览",
+    items: [
+      { href: "/admin", label: "仪表盘", icon: LayoutDashboard, exact: true, visible: () => true },
+    ],
   },
   {
-    href: "/admin/economy",
-    label: "积分看板",
-    icon: Coins,
-    visible: (u) => isAdminOrAbove(u.role),
+    title: "内容",
+    items: [
+      {
+        href: "/admin/moderation",
+        label: "内容审核",
+        icon: ClipboardCheck,
+        visible: (u) => canModerateAny(u),
+        pendingBadge: true,
+      },
+      {
+        href: "/admin/content",
+        label: "内容管理",
+        icon: FolderOpen,
+        visible: (u) => canModerateAny(u),
+      },
+      {
+        href: "/admin/announcements",
+        label: "公告管理",
+        icon: Megaphone,
+        visible: (u) => isAdminOrAbove(u.role),
+      },
+    ],
   },
   {
-    href: "/admin/announcements",
-    label: "公告管理",
-    icon: Megaphone,
-    visible: (u) => isAdminOrAbove(u.role),
+    title: "成员与经济",
+    items: [
+      {
+        href: "/admin/users",
+        label: "用户权限",
+        icon: Users,
+        visible: (u) => isSuperOrOwner(u.role),
+      },
+      {
+        href: "/admin/economy",
+        label: "积分看板",
+        icon: Coins,
+        visible: (u) => isAdminOrAbove(u.role),
+      },
+    ],
   },
   {
-    href: "/admin/users",
-    label: "用户权限",
-    icon: Users,
-    visible: (u) => isSuperOrOwner(u.role),
-  },
-  {
-    href: "/admin/appearance",
-    label: "外观设置",
-    icon: Palette,
-    visible: (u) => isSuperOrOwner(u.role),
+    title: "站点",
+    items: [
+      {
+        href: "/admin/settings",
+        label: "站点设置",
+        icon: Globe,
+        visible: (u) => isSuperOrOwner(u.role),
+      },
+      {
+        href: "/admin/appearance",
+        label: "外观",
+        icon: Palette,
+        visible: (u) => isSuperOrOwner(u.role),
+      },
+    ],
   },
 ];
 
@@ -78,7 +115,6 @@ function isActive(pathname: string, href: string, exact?: boolean) {
   return exact ? pathname === href : pathname === href || pathname.startsWith(`${href}/`);
 }
 
-/** 待审核数量：首屏 + WS 推送 + 回前台校准（无定时轮询） */
 function usePendingCounts(enabled: boolean) {
   const [counts, setCounts] = useState({ posts: 0, comments: 0 });
   useEffect(() => {
@@ -116,19 +152,24 @@ function PendingBadge({ count }: { count: number }) {
   );
 }
 
-/**
- * 桌面端后台侧边栏：品牌头 + 分组导航 + 返回站点 + 身份卡。
- * 选中态复用全站导航语言（--nav-active-bg 淡底 + accent 文字），
- * 与 j13-bcard / 顶部 pill 保持一致。
- */
+function visibleGroups(user: RoleUserLike) {
+  return NAV_GROUPS.map((g) => ({
+    ...g,
+    items: g.items.filter((i) => i.visible(user)),
+  })).filter((g) => g.items.length > 0);
+}
+
+function flatItems(user: RoleUserLike) {
+  return visibleGroups(user).flatMap((g) => g.items);
+}
+
 export function AdminSidebar({ user }: { user: User }) {
   const pathname = usePathname();
-  const items = NAV_ITEMS.filter((i) => i.visible(user));
-  const pendingTotal = usePendingCounts(items.some((i) => i.pendingBadge));
+  const groups = visibleGroups(user);
+  const pendingTotal = usePendingCounts(flatItems(user).some((i) => i.pendingBadge));
 
   return (
     <div className="panel p-3">
-      {/* 品牌头 */}
       <div className="flex items-center gap-2.5 px-2 pt-1.5 pb-3.5" style={{ borderBottom: "1px solid var(--line)" }}>
         <span
           className="w-9 h-9 rounded-xl flex items-center justify-center shrink-0"
@@ -146,35 +187,39 @@ export function AdminSidebar({ user }: { user: User }) {
         </span>
       </div>
 
-      {/* 导航 */}
-      <nav className="flex flex-col gap-1 pt-3 pb-2" aria-label="后台导航">
-        <p className="field-label px-2 pb-1.5" style={{ marginBottom: 0 }}>
-          站点管理
-        </p>
-        {items.map((item) => {
-          const active = isActive(pathname, item.href, item.exact);
-          const Icon = item.icon;
-          return (
-            <Link
-              key={item.href}
-              href={item.href}
-              aria-current={active ? "page" : undefined}
-              className="flex items-center gap-2.5 px-3 py-2.5 rounded-xl text-[13.5px] font-medium transition-colors"
-              style={
-                active
-                  ? { background: "var(--nav-active-bg)", color: "var(--nav-active-ink)" }
-                  : { color: "var(--ink-2)" }
-              }
-            >
-              <Icon size={16} className="shrink-0" style={{ color: active ? "var(--nav-active-ink)" : "var(--ink-3)" }} />
-              {item.label}
-              {item.pendingBadge && <PendingBadge count={pendingTotal} />}
-            </Link>
-          );
-        })}
+      <nav className="flex flex-col gap-3 pt-3 pb-2" aria-label="后台导航">
+        {groups.map((group) => (
+          <div key={group.title}>
+            <p className="field-label px-2 pb-1.5" style={{ marginBottom: 0 }}>
+              {group.title}
+            </p>
+            <div className="flex flex-col gap-1">
+              {group.items.map((item) => {
+                const active = isActive(pathname, item.href, item.exact);
+                const Icon = item.icon;
+                return (
+                  <Link
+                    key={item.href}
+                    href={item.href}
+                    aria-current={active ? "page" : undefined}
+                    className="flex items-center gap-2.5 px-3 py-2.5 rounded-xl text-[13.5px] font-medium transition-colors"
+                    style={
+                      active
+                        ? { background: "var(--nav-active-bg)", color: "var(--nav-active-ink)" }
+                        : { color: "var(--ink-2)" }
+                    }
+                  >
+                    <Icon size={16} className="shrink-0" style={{ color: active ? "var(--nav-active-ink)" : "var(--ink-3)" }} />
+                    {item.label}
+                    {item.pendingBadge && <PendingBadge count={pendingTotal} />}
+                  </Link>
+                );
+              })}
+            </div>
+          </div>
+        ))}
       </nav>
 
-      {/* 返回前台 */}
       <div className="pt-2" style={{ borderTop: "1px solid var(--line)" }}>
         <Link
           href="/"
@@ -186,7 +231,6 @@ export function AdminSidebar({ user }: { user: User }) {
         </Link>
       </div>
 
-      {/* 身份卡：按当前角色显示对应徽章（站长为皇冠标识） */}
       <div className="flex items-center gap-2.5 mt-2 px-2.5 py-2.5 rounded-xl" style={{ background: "var(--panel-2)" }}>
         <Avatar name={user.nickname || user.username} src={user.avatar || undefined} size={32} />
         <div className="min-w-0 leading-tight">
@@ -205,13 +249,9 @@ export function AdminSidebar({ user }: { user: User }) {
   );
 }
 
-/**
- * 移动端后台导航：横向滚动 pill，吸附在全站 Header 下方，
- * 窄屏下保持与桌面侧栏同等的切换能力且不占垂直空间。
- */
 export function AdminNavMobile({ user }: { user: User }) {
   const pathname = usePathname();
-  const items = NAV_ITEMS.filter((i) => i.visible(user));
+  const items = flatItems(user);
   const pendingTotal = usePendingCounts(items.some((i) => i.pendingBadge));
 
   return (