feat(auth): 分享卡直达详情页未登录时先跳登录，登录后回跳原页面

- 家庭详情页 useDidShow 检测无 token 时 reLaunch 登录页并携带 redirect 参数
- 登录页登录成功/已有 token 时优先回跳 redirect 目标，无参数仍进首页

src/pages/family/detail.tsx

@@ -1,6 +1,7 @@
 import { useState } from 'react'
 import { useRouter, useDidShow, useShareAppMessage } from '@tarojs/taro'
 import { View, Text, Button } from '@tarojs/components'
+import { useAppSelector } from '@/store/hooks'
 import { Navbar } from '@/components/navbar'
 import { Loading } from '@/components/loading'
 import { StateView } from '@/components/state-view'
@@ -10,7 +11,7 @@ import { getHomeDetail, getHomeMemberList, type HomeInfo, type HomeMember } from
 import { getCareMemberList, type CareMember } from '@/api/careMember'
 import { MAX_CARED_PER_FAMILY } from '@/constants/family'
 import { ROUTES } from '@/constants/routes'
-import { navigateBack, navigateTo } from '@/utils/navigation'
+import { navigateBack, navigateTo, reLaunch } from '@/utils/navigation'
 import { showToast } from '@/utils/toast'
 import styles from './detail.module.scss'
 
@@ -29,6 +30,7 @@ const contactsSummary = (c: CareMember): string => {
 export default function FamilyDetail() {
   const router = useRouter()
   const familyId = router.params.id ?? ''
+  const token = useAppSelector((s) => s.auth.token)
 
   const [loading, setLoading] = useState(true)
   const [family, setFamily] = useState<HomeInfo | null>(null)
@@ -36,6 +38,12 @@ export default function FamilyDetail() {
   const [caredList, setCaredList] = useState<CareMember[]>([])
 
   const load = async () => {
+    // 分享卡直达本页且未登录：先去登录，登录后回跳本页
+    if (!token) {
+      const target = encodeURIComponent(`${ROUTES.FAMILY_DETAIL}?id=${familyId}&invite=1`)
+      reLaunch(`${ROUTES.LOGIN}?redirect=${target}`)
+      return
+    }
     setLoading(true)
     try {
       const [home, memberList, careList] = await Promise.all([

src/pages/login/index.tsx

@@ -1,6 +1,6 @@
 import { useState } from 'react'
 import { View, Text } from '@tarojs/components'
-import { useDidShow } from '@tarojs/taro'
+import { useRouter, useDidShow } from '@tarojs/taro'
 import { useAppDispatch, useAppSelector } from '@/store/hooks'
 import { setAuth } from '@/store/authSlice'
 import { performWxLogin, completeUserInfoLogin, getLoginSubState } from './wxLoginFlow'
@@ -14,15 +14,23 @@ import styles from './index.module.scss'
 export default function Login() {
   const dispatch = useAppDispatch()
   const toast = useToast()
+  const router = useRouter()
   const token = useAppSelector((s) => s.auth.token)
   const [loading, setLoading] = useState(false)
   // 注册中间态：needUserInfo（待用户资料授权）→ null（初始/完成）
   const [needAuth, setNeedAuth] = useState(false)
   const [openId, setOpenId] = useState('')
 
+  // 登录后落地页：携带 redirect 参数时优先回跳（守卫踢登录/分享卡直达场景），否则进首页
+  const afterLoginUrl = () => {
+    const raw = router.params.redirect
+    const target = typeof raw === 'string' && raw.startsWith('/') ? decodeURIComponent(raw) : ''
+    return target || ROUTES.HOME
+  }
+
   // 已有 token 直接进首页（本期不做 checkLogin 校验，spec D5）
   useDidShow(() => {
-    if (token && !loading) reLaunch(ROUTES.HOME)
+    if (token && !loading) reLaunch(afterLoginUrl())
   })
 
   // 完整登录态校验与落地；未完成时推进授权态
@@ -49,7 +57,7 @@ export default function Login() {
     console.log('[login-page] 登录完成，token 已落地')
     setNeedAuth(false)
     dispatch(setAuth({ token, userInfo: result.userInfo }))
-    await reLaunch(ROUTES.HOME)
+    await reLaunch(afterLoginUrl())
   }
 
   const handleWxLogin = async () => {