iter(g173): 上传图片显示缩略图

packages/skin/ui/src/upload.ts

@@ -36,13 +36,24 @@ export function upload(props: UploadProps): HTMLElement {
     sync();
   };
 
+  // —— 图片缩略图：对象 URL 按 File 缓存，文件离场即释放（否则整页存活期都在泄漏） ——
+  const urls = new Map<File, string>();
+  const thumbOf = (file: File): HTMLElement | null => {
+    if (!file.type.startsWith('image/')) return null; // 卫语句：非图片不缩略，只给文件名
+    let url = urls.get(file);
+    if (!url) { url = URL.createObjectURL(file); urls.set(file, url); }
+    return h('img', { class: 'ua-upload-thumb', src: url, alt: '', loading: 'lazy' });
+  };
+
   /*** 重绘清单并回传（选择/拖拽/移除都走这里，保证单一出口） ***/
   const sync = (tip = '') => {
+    for (const [file, url] of urls) if (!files.includes(file)) { URL.revokeObjectURL(url); urls.delete(file); } // 已离场的文件先释放
     listEl.replaceChildren(
       ...files.map((file, i) =>
         h(
           'div',
           { class: 'ua-upload-item' },
+          thumbOf(file),
           h('span', { class: 'ua-upload-name' }, file.name),
           h('span', { class: 'ua-upload-size' }, size(file.size)),
           h('button', { type: 'button', class: 'ua-upload-remove', 'aria-label': `移除 ${file.name}`, onclick: () => remove(i) }, '×'),