fix: 前端统一解析后端 detail 报错，杜绝 [object Object]

各处 catch 里直接 `toast(err?.response?.data?.detail ?? "xx失败")` 有坑：
请求体校验失败(422)时 detail 是数组，React 会把每个对象渲染成 [object Object]。

- utils/errorMessage.ts（新增）: extractErrorMessage 统一解析三种形态 ——
  字符串 / FastAPI 校验错误数组 / 对象；数组取 msg 并剥掉 Pydantic 的
  "Value error, " 前缀、带上字段名、同字段去重后用「；」拼接；解析不出内容
  则回落到调用方给的兜底文案。行为与移动端 extractErrorDetail 对齐
- 19 处调用点全部替换：AdminTasksPage(4) / AdminProductsPage(5) /
  TaskTreeViewer(4) / AdminPrintConfigPage(2) / ScanPage / CreateProductDialog /
  ImageUploader / authApi
- TaskRejectPayload.images 与 taskApi.rejectTask 的注释同步为「选填，支持空数组」
- 新增 components/ui/ImageUploader.tsx（驳回弹窗选图上传组件），
  RejectModal 同步放开无图拦截：去掉 images 非空校验、提交按钮不再因
  无图禁用、标签由必填星号改为「（选填，最多 9 张）」，并移除因此失效的
  error 状态
- AdminTasksPage.tsx: 支持大屏下钻的 ?search / ?status / ?stage 预设参数，
  新增「售后流转中」状态 Tab（按 lifecycle_phase 判定）与全局重置；
  ?stage 只在跳入时生效一次，用户手动改条件即解除锁定
- 杂项清理: TaskFlowView 移除透传的 assigneeNames、TaskListCard/MyTasksPage
  移除未使用导入、QrScanner 关闭 verbose 日志

frontend/src/pages/admin/AdminProductsPage.tsx

@@ -14,6 +14,7 @@ import {
 import { useToast } from "../../components/ui/Toast";
 import { useAuth } from "../../contexts/AuthContext";
 import { getStatusConfig, lifecycleBadge } from "../../constants/task";
+import { extractErrorMessage } from "../../utils/errorMessage";
 
 const QR_BASE = "/api/v1/products/qrcode";
 
@@ -125,12 +126,12 @@ export default function AdminProductsPage() {
   }
 
   // ---- 打印 ----
-  async function handleOpenPrint(product: ProductResponse) { /* unchanged */ setPrintTarget(product); setPreviewUrl(null); setPrintCopies(1); setPrintLoading(true); try { setPreviewUrl(await getLabelPreview({ serial_number: product.serial_number, material_name: product.material_name ?? product.material_id ?? "", spec_model: product.spec_model ?? "", order_no: product.order_no ?? "" })); } catch (err: any) { toast(err?.response?.data?.detail ?? "生成预览失败", "error"); setPrintTarget(null); } finally { setPrintLoading(false); } }
-  async function handleConfirmPrint() { if (!printTarget) return; setPrinting(true); try { const r = await executePrint({ serial_number: printTarget.serial_number, material_name: printTarget.material_name ?? "", spec_model: printTarget.spec_model ?? "", order_no: printTarget.order_no ?? "", copies: printCopies }); toast(r.message, "success"); setPrintTarget(null); } catch (err: any) { toast(err?.response?.data?.detail ?? "打印失败", "error"); } finally { setPrinting(false); } }
+  async function handleOpenPrint(product: ProductResponse) { /* unchanged */ setPrintTarget(product); setPreviewUrl(null); setPrintCopies(1); setPrintLoading(true); try { setPreviewUrl(await getLabelPreview({ serial_number: product.serial_number, material_name: product.material_name ?? product.material_id ?? "", spec_model: product.spec_model ?? "", order_no: product.order_no ?? "" })); } catch (err: unknown) { toast(extractErrorMessage(err, "生成预览失败"), "error"); setPrintTarget(null); } finally { setPrintLoading(false); } }
+  async function handleConfirmPrint() { if (!printTarget) return; setPrinting(true); try { const r = await executePrint({ serial_number: printTarget.serial_number, material_name: printTarget.material_name ?? "", spec_model: printTarget.spec_model ?? "", order_no: printTarget.order_no ?? "", copies: printCopies }); toast(r.message, "success"); setPrintTarget(null); } catch (err: unknown) { toast(extractErrorMessage(err, "打印失败"), "error"); } finally { setPrinting(false); } }
 
   // ---- 编辑 ----
   function openEdit(p: ProductResponse) { setEditTarget(p); setEditOrderNo(p.order_no ?? ""); setEditExternalSerial(p.external_serial ?? ""); }
-  async function handleSaveEdit() { if (!editTarget) return; setEditSaving(true); try { await api.patch(`/products/${editTarget.id}`, { order_no: editOrderNo.trim() || null, external_serial: editExternalSerial.trim() || null }); toast("保存成功", "success"); setEditTarget(null); loadProducts(); } catch (err: any) { toast(err?.response?.data?.detail ?? "保存失败", "error"); } finally { setEditSaving(false); } }
+  async function handleSaveEdit() { if (!editTarget) return; setEditSaving(true); try { await api.patch(`/products/${editTarget.id}`, { order_no: editOrderNo.trim() || null, external_serial: editExternalSerial.trim() || null }); toast("保存成功", "success"); setEditTarget(null); loadProducts(); } catch (err: unknown) { toast(extractErrorMessage(err, "保存失败"), "error"); } finally { setEditSaving(false); } }
 
   // ---- 删除 ----
   useEffect(() => {
@@ -141,7 +142,7 @@ export default function AdminProductsPage() {
   }, [deleteTarget?.id]); // eslint-disable-line
 
   function confirmDelete(p: ProductResponse) { setDeleteTarget(p); }
-  async function handleDelete() { if (!deleteTarget) return; setDeleting(true); try { await api.delete(`/products/${deleteTarget.id}`); toast("已删除", "success"); setDeleteTarget(null); loadProducts(); } catch (err: any) { toast(err?.response?.data?.detail ?? "删除失败", "error"); } finally { setDeleting(false); } }
+  async function handleDelete() { if (!deleteTarget) return; setDeleting(true); try { await api.delete(`/products/${deleteTarget.id}`); toast("已删除", "success"); setDeleteTarget(null); loadProducts(); } catch (err: unknown) { toast(extractErrorMessage(err, "删除失败"), "error"); } finally { setDeleting(false); } }
 
   // ---- 状态收口（入库 / 出库，管理员）----
   // 🛡️ 双重确认倒计时 + 必须输入产品身份证，防误触
@@ -164,8 +165,8 @@ export default function AdminProductsPage() {
       toast(`已收口为「${finalizeStatus}」`, "success");
       setFinalizeTarget(null);
       loadProducts();
-    } catch (err: any) {
-      toast(err?.response?.data?.detail ?? "操作失败", "error");
+    } catch (err: unknown) {
+      toast(extractErrorMessage(err, "操作失败"), "error");
     } finally {
       setFinalizing(false);
     }