[ADMIN] How to investigate a failed Stripe webhook

1. Stripe Dashboard → Developers → Webhooks → pick the endpoint.
2. Find the failed delivery (status Failed or Pending retry).
3. View the response body — look for PHP error or non-200 status.
4. Cross-reference with wp-content/debug.log at the same timestamp.
5. Common causes: signing secret mismatch, plugin deactivated, fatal error in webhook handler, 502 from server.
6. Once fixed, click Resend in Stripe to replay the event.
7. Verify the side effect ran (tenant created, subscription extended, etc.).