fix(coding): recover provider context failures

shared/ai-gateway-error-details.ts

@@ -4,3 +4,8 @@ export function isAIGatewayUpstreamSaturated(message: string | null | undefined)
   return normalized.includes('当前分组上游负载已饱和')
     || (normalized.includes('upstream') && normalized.includes('saturat'));
 }
+
+export function isAIGatewayUserContextMissing(message: string | null | undefined): boolean {
+  const normalized = message?.trim().toLowerCase() ?? '';
+  return normalized.includes('works square ai gateway did not return one-api user context');
+}