feat: 交互优化与代码质量改进

- SvgIcon 改为 PNG 图标方案，组件重命名为 Icon
- 修复 TransactionItem tap 事件名冲突，改为 item-tap
- 修复 Stats 页面切换 tab 时 overview 不更新
- 修复 CategoryIcon bgColor 必填问题
- 修复 ChartWrapper import 顺序
- 修复 budget onDelete 空字符串问题
- 清理 profile 页面未使用 CSS
- 统一所有页面 header 为 sticky 定位
- 修复导航栏返回按钮不统一
- 添加导出功能 loading 状态
- 优化 scroll-into-view 延迟

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

@@ -1,12 +1,14 @@
 <template>
   <view class="page">
-    <view class="status-bar" :style="{ height: statusBarHeight + 'px' }"></view>
-    <view class="header">
-      <view class="back" @tap="uni.navigateBack()">
-        <SvgIcon name="arrowLeft" :size="36" color="#2D1B1B" />
+    <view class="header-fixed">
+      <view class="status-bar" :style="{ height: statusBarHeight + 'px' }"></view>
+      <view class="header">
+        <view class="nav-back" @tap="goBack">
+          <Icon name="arrowLeft" :size="36" color="#2D1B1B" />
+        </view>
+        <text class="title">分类管理</text>
+        <view style="width: 88rpx;"></view>
       </view>
-      <text class="title">分类管理</text>
-      <view style="width: 88rpx;"></view>
     </view>
 
     <view class="tabs-wrap">
@@ -24,7 +26,7 @@
           <text class="cat-badge" v-if="cat.is_custom">自定义</text>
         </view>
         <view class="cat-actions" v-if="cat.is_custom" @tap="onDelete(cat)">
-          <SvgIcon name="trash" :size="28" color="#FF6B6B" />
+          <Icon name="trash" :size="28" color="#FF6B6B" />
         </view>
       </view>
     </view>
@@ -52,7 +54,7 @@
 import { ref, computed, onMounted } from 'vue'
 import { useCategoryStore } from '@/stores/category'
 import CategoryIcon from '@/components/CategoryIcon/CategoryIcon.vue'
-import SvgIcon from '@/components/SvgIcon/SvgIcon.vue'
+import Icon from '@/components/Icon/Icon.vue'
 import { statusBarHeight } from '@/utils/system'
 
 const catStore = useCategoryStore()
@@ -65,6 +67,10 @@ const currentCategories = computed(() => catStore.getByType(tabType.value))
 
 onMounted(() => catStore.fetchCategories())
 
+function goBack() {
+  uni.navigateBack()
+}
+
 async function onAdd() {
   const name = newName.value.trim()
   if (!name) return
@@ -132,6 +138,13 @@ async function onDelete(cat: any) {
   padding: 0 0 180rpx;
 }
 
+.header-fixed {
+  position: sticky;
+  top: 0;
+  z-index: 100;
+  background: #FFF8F0;
+}
+
 .status-bar { background: #FFF8F0; }
 
 .header {
@@ -141,12 +154,15 @@ async function onDelete(cat: any) {
   padding: 16rpx 40rpx;
 }
 
-.back {
+.nav-back {
   width: 88rpx;
   height: 88rpx;
   display: flex;
   align-items: center;
   justify-content: center;
+  border-radius: 50%;
+
+  &:active { background: #F0E0D6; }
 }
 
 .title { font-size: 32rpx; font-weight: 600; color: #2D1B1B; }