feat: 品牌文案配置化 + 全页面下拉刷新

- 新增 configStore 管理品牌文案（appName, appSlogan, appDescription）
- 关于弹窗、分享标题使用 configStore 读取品牌名
- 所有数据页面添加下拉刷新功能
- 所有数据页面 onShow 时自动刷新数据

client/src/pages/group-manage/index.vue

@@ -140,8 +140,9 @@
 
 <script setup lang="ts">
 import { ref, onMounted } from 'vue'
-import { onShow, onShareAppMessage, onShareTimeline } from '@dcloudio/uni-app'
+import { onShow, onPullDownRefresh, onShareAppMessage, onShareTimeline } from '@dcloudio/uni-app'
 import { useGroupStore } from '@/stores/group'
+import { useConfigStore } from '@/stores/config'
 import { waitForReady } from '@/utils/app-ready'
 import { statusBarHeight, capsuleRight } from '@/utils/system'
 import { API_BASE } from '@/config'
@@ -149,6 +150,7 @@ import Icon from '@/components/Icon/Icon.vue'
 import type { GroupMember, Group } from '@/api/group'
 
 const groupStore = useGroupStore()
+const configStore = useConfigStore()
 
 const actionTab = ref<'create' | 'join'>('create')
 const newGroupName = ref('')
@@ -174,6 +176,11 @@ onShow(() => {
   if (initialLoaded.value) groupStore.fetchGroups()
 })
 
+onPullDownRefresh(async () => {
+  await groupStore.fetchGroups()
+  uni.stopPullDownRefresh()
+})
+
 // #ifdef MP-WEIXIN
 onShareAppMessage(() => {
   // 空值保护：通过右上角菜单触发时 invite_code 可能为空
@@ -188,7 +195,7 @@ onShareAppMessage(() => {
 })
 
 onShareTimeline(() => ({
-  title: '小菜记账 — 一起来记账吧！'
+  title: `${configStore.appName} — 一起来记账吧！`
 }))
 // #endif