fix(client): 修复导入静默失败问题

捕获所有异常（非仅 DioException），兼容 ImportProducts 响应格式（无 total/skipped），
确保任何错误都在 UI 上显示而不是静默消失。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/screens/settings/settings_screen.dart

@@ -1514,19 +1514,25 @@ class _BatchImportWidgetState extends ConsumerState<_BatchImportWidget> {
           'file': MultipartFile.fromBytes(bytes, filename: slot.file!.name),
         });
         final resp = await dio.post(slot.endpoint, data: formData);
-        final data = resp.data as Map<String, dynamic>;
+        final data = (resp.data is Map) ? resp.data as Map<String, dynamic> : <String, dynamic>{};
         if (mounted) setState(() {
           slot.success = true;
-          slot.total = (data['total'] ?? 0) as int;
+          slot.total = (data['total'] ?? data['imported'] ?? 0) as int;
           slot.imported = (data['imported'] ?? 0) as int;
           slot.skipped = (data['skipped'] ?? 0) as int;
         });
       } on DioException catch (e) {
-        final msg = (e.response?.data as Map?)?['error'] ?? e.message ?? '未知错误';
+        final raw = e.response?.data;
+        final msg = (raw is Map ? raw['error'] : null) ?? e.message ?? '未知错误';
         if (mounted) setState(() {
           slot.success = false;
           slot.error = msg.toString();
         });
+      } catch (e) {
+        if (mounted) setState(() {
+          slot.success = false;
+          slot.error = e.toString();
+        });
       }
     }