feat(image-cache): 新增图片本地缓存并全站接入

引入 cached-image 组件与 image-cache 工具，实现签名 URL 稳定 key 剥离、downloadFile 落盘及 TTL/LRU 清理，替换 11 个页面与 clothes-card 共 22 处网络图片渲染点，减少 CDN 重复流量。

miniprogram/pages/closet-share-detail/closet-share-detail.wxml

@@ -28,7 +28,7 @@
 
     <view class="csd-owner">
       <view class="csd-av">
-        <image wx:if="{{detail.owner_avatar}}" class="pic" src="{{detail.owner_avatar}}" mode="aspectFill" />
+        <cached-image wx:if="{{detail.owner_avatar}}" class="pic" src="{{detail.owner_avatar}}" mode="aspectFill" />
         <view wx:else class="icon icon-user"></view>
       </view>
       <view class="csd-owner-body">
@@ -41,7 +41,7 @@
     <view class="csd-grid">
       <view class="csd-tile" wx:for="{{detail.clothes}}" wx:key="clothes_uuid">
         <view class="tile-img">
-          <image wx:if="{{item.processed_image}}" class="pic" src="{{item.processed_image}}" mode="aspectFill" lazy-load />
+          <cached-image wx:if="{{item.processed_image}}" class="pic" src="{{item.processed_image}}" mode="aspectFill" lazy-load="{{true}}" />
           <view wx:else class="ph icon icon-hanger"></view>
         </view>
         <view class="tile-name">{{item.name || '未命名'}}</view>