fix: 全面修复 22 项问题

严重 Bug:
- NaN 金额校验绕过（add 页面 parseFloat 空字符串）
- 4 个页面补充 waitForReady（add/budget/category-manage/group-manage）
- 导出 Loading 遮罩不消失（profile exportData 缺 hideLoading）
- Store 吞掉请求错误不 re-throw（transaction/stats/budget/user）
- 分类排序 SQL 拼接改参数化查询（category PUT /sort）
- 备份接口添加管理员权限检查（backup requireAdmin）

中等问题:
- 群组加入竞态条件改为 INSERT IGNORE
- 统计页切月/切Tab添加 loadSeq 防竞态
- stats store 补全 loading 状态 + Overview 初始值补全 7 字段
- 保存成功后返回不再弹「放弃修改」确认框
- 群组管理创建/加入添加 saving 双重提交保护
- 预算页添加 onShow 刷新
- 服务端输入校验（name/color/invite_code/微信code）

UI/样式:
- 触摸目标: bell/nav-back/nav-save→88rpx, avatar-badge→64rpx, action-btn→80rpx
- :active 反馈: bell/profile-card/identity-card/id-manage/arrow/action-btn/group-btn/cat-info
- 内联样式改动态绑定（4处 spacer 使用 capsuleRight）
- FAB 文字+改用 Icon 组件
- prefers-reduced-motion 动画降级（Skeleton/profile/budget/add）
- 胶囊适配（add/category-manage/group-manage）
- CategoryIcon !important 改为 iconStyle 计算属性

文档:
- CLAUDE.md 补充 SaveSuccess/ChartWrapper 组件 + category/budget/index API

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

@@ -7,7 +7,7 @@
           <Icon name="arrowLeft" :size="40" color="#2D1B1B" />
         </view>
         <text class="nav-title">一起记</text>
-        <view style="width: 72rpx;"></view>
+        <view :style="{ width: capsuleRight + 72 + 'px' }"></view>
       </view>
     </view>
 
@@ -77,15 +77,18 @@
 <script setup lang="ts">
 import { ref, onMounted } from 'vue'
 import { useGroupStore } from '@/stores/group'
-import { statusBarHeight } from '@/utils/system'
+import { waitForReady } from '@/utils/app-ready'
+import { statusBarHeight, capsuleRight } from '@/utils/system'
 import Icon from '@/components/Icon/Icon.vue'
 
 const groupStore = useGroupStore()
 
 const newGroupName = ref('')
 const inviteCode = ref('')
+const saving = ref(false)
 
-onMounted(() => {
+onMounted(async () => {
+  await waitForReady()
   groupStore.fetchGroups()
 })
 
@@ -101,11 +104,13 @@ function copyInviteCode(code: string) {
 }
 
 async function handleCreate() {
+  if (saving.value) return
   const name = newGroupName.value.trim()
   if (!name) {
     uni.showToast({ title: '请输入群组名称', icon: 'none' })
     return
   }
+  saving.value = true
   try {
     const result = await groupStore.createGroup(name)
     newGroupName.value = ''
@@ -121,21 +126,27 @@ async function handleCreate() {
     })
   } catch (e: any) {
     uni.showToast({ title: e.message || '创建失败', icon: 'none' })
+  } finally {
+    saving.value = false
   }
 }
 
 async function handleJoin() {
+  if (saving.value) return
   const code = inviteCode.value.trim().toUpperCase()
   if (!code) {
     uni.showToast({ title: '请输入邀请码', icon: 'none' })
     return
   }
+  saving.value = true
   try {
     const result = await groupStore.joinGroup(code)
     inviteCode.value = ''
     uni.showToast({ title: `已加入「${result.name}」`, icon: 'success' })
   } catch (e: any) {
     uni.showToast({ title: e.message || '加入失败', icon: 'none' })
+  } finally {
+    saving.value = false
   }
 }
 
@@ -197,11 +208,13 @@ function handleDissolve(group: any) {
 }
 
 .nav-back {
-  width: 72rpx;
-  height: 72rpx;
+  width: 88rpx;
+  height: 88rpx;
   display: flex;
   align-items: center;
   justify-content: center;
+
+  &:active { opacity: 0.6; }
 }
 
 .nav-title {
@@ -336,6 +349,8 @@ function handleDissolve(group: any) {
   display: flex;
   align-items: center;
   margin-top: 8rpx;
+  padding: 8rpx 0;
+  min-height: 48rpx;
   gap: 4rpx;
 }
 
@@ -363,11 +378,17 @@ function handleDissolve(group: any) {
 }
 
 .group-btn {
-  padding: 12rpx 24rpx;
+  padding: 16rpx 28rpx;
   border-radius: 16rpx;
+  min-height: 48rpx;
+  display: flex;
+  align-items: center;
+  justify-content: center;
 
   &.leave { background: #FFF0E6; }
   &.dissolve { background: #FFE8E8; }
+
+  &:active { opacity: 0.7; }
 }
 
 .group-btn-text {