修复首次会话等待与上游饱和重试

electron/api/routes/ai-proxy.ts

@@ -9,6 +9,7 @@ import {
 import { proxyAwareFetch } from '../../utils/proxy-fetch';
 import { logger } from '../../utils/logger';
 import { getOpencodeErrorKind } from '../../../shared/opencode-error-kind';
+import { isOpencodeUpstreamSaturated } from '../../../shared/opencode-error-details';
 
 const AI_PROXY_PREFIX = '/api/ai-proxy/v1';
 const MAX_ERROR_LOG_MESSAGE_LENGTH = 600;
@@ -81,6 +82,9 @@ function getForwardedOneApiStatus(status: number, bodyText: string): number {
   if (status === 429 && getOpencodeErrorKind(bodyText) === 'quota_exhausted') {
     return 402;
   }
+  if (status === 429 && isOpencodeUpstreamSaturated(bodyText)) {
+    return 400;
+  }
   return status;
 }