merchantPost now retries once after clearing the cached token and re-authenticating when the upstream signals an invalid session: HTML login page, HTTP 401, or business msgs containing login-expiry keywords. Previously a stale token left stock queries returning empty until manual intervention. Generated with [Devin](https://devin.ai) Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>