chore(backlog): 记录 g173 完成

.ua/backlog.json

@@ -1740,6 +1740,14 @@
       "acceptance": "ua list --json 输出 {name, version, type, description, components[]} 数组，--components 仍逐组件展开；CLI 清单 exports 与 AGENTS.md 的用法行同步；npm run check 全绿（含 lint-iterations）。",
       "notes": "",
       "status": "done"
+    },
+    {
+      "id": "g173",
+      "title": "上传图片显示缩略图",
+      "motivation": "选完图片只看到文件名，用户没法确认选的是哪张——上传头像 / 凭证照这类场景必须点开本地文件核对，体验很别扭。",
+      "acceptance": "upload 对 image/* 文件渲染 28px 缩略图（object-fit: cover），对象 URL 按 File 缓存、文件离场即 revoke；非图片保持文件名 + 体积；manifest 步骤、llms-full 同步；npm run check 全绿。",
+      "notes": "",
+      "status": "done"
     }
   ]
 }

.ua/iterations.log

@@ -217,3 +217,4 @@
 {"ts":"2026-10-26T16:17:06+08:00","id":"g170","result":"done","commit":"a754bd6","summary":"pagination 新增 simple 极简模式与 hideOnSinglePage"}
 {"ts":"2026-10-26T16:17:49+08:00","id":"g171","result":"done","commit":"6a605ba","summary":"刷新 CHANGELOG 至 400 提交，补 llms.txt 的配方 11 目录行"}
 {"ts":"2026-10-26T16:19:32+08:00","id":"g172","result":"done","commit":"250601d","summary":"ua list 新增 --json（包 + 组件 id 结构化输出），CLI 清单与 AGENTS 同步"}
+{"ts":"2026-10-26T16:20:30+08:00","id":"g173","result":"done","commit":"ea4e781","summary":"upload 图片文件带 28px 缩略图，对象 URL 随文件离场 revoke"}