Fix validación en hero() y CORS para ngrok

- SupplierController: corregir respuesta de error del validador, bank_account acepta numeric, rfc/bank/bank_account required al crear
- Cors: permitir header ngrok-skip-browser-warning

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Http/Middleware/Cors.php

@@ -31,7 +31,7 @@ class Cors
             return $response
                 ->header('Access-Control-Allow-Origin', $allowOrigin)
                 ->header('Access-Control-Allow-Methods', 'GET, POST, PUT, PATCH, DELETE, OPTIONS')
-                ->header('Access-Control-Allow-Headers', 'Content-Type, Authorization, X-Requested-With, X-XSRF-TOKEN');
+                ->header('Access-Control-Allow-Headers', 'Content-Type, Authorization, X-Requested-With, X-XSRF-TOKEN, ngrok-skip-browser-warning');
         }
 
         return $next($request);