feat(usercenter): SSO /sso 落地页(拿票兑会话→自动登录)

App 打开 app.yanmeiai.com/sso?t=<ticket>&redirect=<路径>;本页 exchangeWebTicket→setSession
(与正常登录同路径)→跳白名单相对路径。镜像 jiu sso.njk。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nMthbVEmQquxBRKb9Fj8u

web/usercenter/lib/api/errors.ts

@@ -18,6 +18,7 @@ export const ERROR_TEXT: Record<string, { zh: string; en: string }> = {
   device_limit: { zh: '设备数量已达上限', en: 'Device limit reached' },
   device_not_found: { zh: '设备不存在', en: 'Device not found' },
   unauthorized: { zh: '登录已失效,请重新登录', en: 'Session expired, please log in again' },
+  'auth.ticket_invalid': { zh: '登录票据无效或已过期，请重新从 App 打开', en: 'Login ticket is invalid or expired, please reopen from the app' },
   network: { zh: '网络异常,请稍后重试', en: 'Network error, please retry' },
   unknown: { zh: '操作失败,请稍后重试', en: 'Something went wrong, please retry' },
 };