fix(file): 透出 IAM 资质登记的真实业务错误，避免误报为服务不可用

- 当 IAM 返回 4xx 业务拒绝（如资质已审核通过、企业不存在）时，解析响应体中的 message 并透传给前端
- 补充 WARN 和 ERROR 日志，记录 Feign 异常的 status 和 body，便于排查
- 移除硬编码的在审核中提示，改为根据 IAM 实际返回的状态码和消息动态映射

file/src/main/java/com/baiyue/file/controller/QualificationFileController.java

@@ -6,8 +6,11 @@ import com.baiyue.common.core.exception.BizException;
 import com.baiyue.common.security.AuthenticatedUser;
 import com.baiyue.file.client.IamQualificationClient;
 import com.baiyue.file.service.LocalQualificationStorage;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import feign.FeignException;
 import jakarta.annotation.Resource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.CacheControl;
 import org.springframework.http.MediaType;
@@ -20,8 +23,10 @@ import org.springframework.web.multipart.MultipartFile;
 @RestController
 @RequestMapping("/api/merchant/v1/files/qualifications")
 public class QualificationFileController {
+    private static final Logger LOGGER = LoggerFactory.getLogger(QualificationFileController.class);
     @Resource private LocalQualificationStorage storage;
     @Resource private IamQualificationClient iamClient;
+    @Resource private ObjectMapper objectMapper;
     @Value("${baiyue.security.internal-service-token}") private String internalToken;
 
     @PostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
@@ -44,14 +49,36 @@ public class QualificationFileController {
                     data.tenantStatus(), stored.documentUrl()));
         } catch (RuntimeException exception) {
             storage.delete(stored);
-            if (exception instanceof FeignException feign && feign.status() == 409) {
-                throw new BizException(ResultCode.CONFLICT, "Enterprise information is already under review");
-            }
             if (exception instanceof BizException business) throw business;
+            if (exception instanceof FeignException feign) {
+                LOGGER.warn("IAM 资质登记被拒绝：status={} body={}", feign.status(), feign.contentUTF8());
+                if (feign.status() >= 400 && feign.status() < 500) {
+                    throw new BizException(resultCodeOf(feign.status()), iamMessage(feign));
+                }
+            }
+            LOGGER.error("IAM 资质登记调用失败", exception);
             throw new BizException(ResultCode.SERVICE_UNAVAILABLE, "IAM qualification service is unavailable");
         }
     }
 
+    /** 透出 IAM 返回的业务错误消息，避免把"已审核通过""重复提交"等业务拒绝误报为服务不可用。 */
+    private String iamMessage(FeignException feign) {
+        try {
+            String message = objectMapper.readTree(feign.contentUTF8()).path("message").asText(null);
+            if (message != null && !message.isBlank()) return message;
+        } catch (Exception ignored) { }
+        return "Enterprise qualification submission was rejected";
+    }
+
+    private ResultCode resultCodeOf(int status) {
+        return switch (status) {
+            case 403 -> ResultCode.FORBIDDEN;
+            case 404 -> ResultCode.NOT_FOUND;
+            case 409 -> ResultCode.CONFLICT;
+            default -> ResultCode.BUSINESS_ERROR;
+        };
+    }
+
     @GetMapping("/{fileName}")
     public ResponseEntity<org.springframework.core.io.Resource> download(
             @AuthenticationPrincipal AuthenticatedUser user, @PathVariable String fileName) {