fix(claim): 透出 affiliate_dash 上游错误，便于排查提交 UID 失败

上游 4xx 不再一律打成 502 兜底文案；affiliate_dash 依赖错误优先展示真实 message。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/backend/src/services/platforms/affiliate-dash/http-client.ts

@@ -95,18 +95,20 @@ export async function affiliateDashRequest(input: {
       logExternalHttpPacket('[affiliate-dash/http]', 'HTTP 响应失败', responsePacket, {
         level: 'warn',
       })
-      throw createHttpError(
-        summarizeAffiliateDashMessage(json) || `affiliate-dash 请求失败: HTTP ${response.status}`,
-        {
-          statusCode: 502,
-          errorCode: 'affiliate_dash_http_failed',
-          context: {
-            status: response.status,
-            message: summarizeAffiliateDashMessage(json),
-            body: text,
-          },
+      const upstreamMessage =
+        summarizeAffiliateDashMessage(json) || `affiliate-dash 请求失败: HTTP ${response.status}`
+      // 上游 4xx 透传状态码，便于领取页展示真实原因；5xx 仍归一为 502。
+      const statusCode =
+        response.status >= 400 && response.status < 500 ? response.status : 502
+      throw createHttpError(upstreamMessage, {
+        statusCode,
+        errorCode: 'affiliate_dash_http_failed',
+        context: {
+          status: response.status,
+          message: summarizeAffiliateDashMessage(json),
+          body: text,
         },
-      )
+      })
     }
 
     if (!isAffiliateDashSuccessResponse(json)) {