Adds withExceptions render callback for ValidationException that forces
JSON 422 response when request matches api/webhook/supplier/* — regardless
of Accept header. Default Laravel behavior is 302 redirect for non-JSON
clients, which strips POST body.
Observed on prod 2026-05-25: 76 of 234 supplier webhook hits got 302 (Location: /),
mostly for non-B-prefix projects (client.carmoney.ru, cabinet.caranga.ru,
cashmotor.ru). Supplier doesn't follow 302 redirects on POST, so the
lead body is lost. This fix ensures supplier always sees a meaningful
422 with errors[] instead of a redirect.
Other routes unaffected (render returns null for non-webhook URLs).
Дмитрий
3dfb96ba47