feat: enhance error logging and upstream response tracking for provider failures

src/services/orchestration/fallback_orchestrator.py

@@ -427,6 +427,9 @@ class FallbackOrchestrator:
             )
             # str(cause) 可能为空（如 httpx 超时异常），使用 repr() 作为备用
             error_msg = str(cause) or repr(cause)
+            # 如果是 ProviderNotAvailableException，附加上游响应
+            if hasattr(cause, "upstream_response") and cause.upstream_response:
+                error_msg = f"{error_msg} | 上游响应: {cause.upstream_response[:500]}"
             RequestCandidateService.mark_candidate_failed(
                 db=self.db,
                 candidate_id=candidate_record_id,
@@ -439,6 +442,9 @@ class FallbackOrchestrator:
 
         # 未知错误：记录失败并抛出
         error_msg = str(cause) or repr(cause)
+        # 如果是 ProviderNotAvailableException，附加上游响应
+        if hasattr(cause, "upstream_response") and cause.upstream_response:
+            error_msg = f"{error_msg} | 上游响应: {cause.upstream_response[:500]}"
         RequestCandidateService.mark_candidate_failed(
             db=self.db,
             candidate_id=candidate_record_id,

src/services/request/result.py

@@ -289,11 +289,17 @@ class RequestResult:
             status_code = 500
             error_type = "internal_error"
 
+        # 构建错误消息，包含上游响应信息
+        error_message = str(exception)
+        if isinstance(exception, ProviderNotAvailableException):
+            if exception.upstream_response:
+                error_message = f"{error_message} | 上游响应: {exception.upstream_response[:500]}"
+
         return cls(
             status=RequestStatus.FAILED,
             metadata=metadata,
             status_code=status_code,
-            error_message=str(exception),
+            error_message=error_message,
             error_type=error_type,
             response_time_ms=response_time_ms,
             is_stream=is_stream,