fix: 修复日期格式转换问题

backend/app/api.py

@@ -509,7 +509,16 @@ async def admin_get_users(
         last_login = last_session.created_at.strftime('%Y/%m/%d %H:%M:%S') if last_session and last_session.created_at else None
         
         # 格式化 VIP 到期时间
-        vip_expire_formatted = vip_info["vip_expire_at"].replace('-', '/') if vip_info["vip_expire_at"] else None
+        vip_expire_formatted = None
+        if vip_info["vip_expire_at"]:
+            try:
+                # 将字符串解析为 datetime 对象，然后重新格式化为所需格式
+                from datetime import datetime
+                dt = datetime.strptime(vip_info["vip_expire_at"], '%Y-%m-%d %H:%M:%S')
+                vip_expire_formatted = dt.strftime('%Y/%m/%d %H:%M:%S')
+            except ValueError:
+                # 如果解析失败，使用原始值
+                vip_expire_formatted = vip_info["vip_expire_at"].replace('-', '/')
         
         result.append(AdminUserItem(
             user_id=u.id,

frontend/src/components/AdminPanel.tsx

@@ -259,7 +259,7 @@ export default function AdminPanel({ isOpen, onClose }: AdminPanelProps) {
                                                                 会员
                                                             </span>
                                                             <div className="flex flex-col items-center gap-0.5">
-                                                                <span className="text-[9px] text-gray-600 font-mono">{user.vip_expire_at?.split(' ')[0] || ''}</span>
+                                                                <span className="text-[9px] text-gray-600 font-mono">{user.vip_expire_at?.split(' ')[0].replace(/-/g, '/') || ''}</span>
                                                                 <span className="text-[8px] text-gray-600 font-mono">{user.vip_expire_at?.split(' ')[1] || ''}</span>
                                                             </div>
                                                         </div>