feat: retry api requests when closed immediately due to overload

src/BusProNet/Exception/ImmediateConnectionCloseException.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\BusProNet\Exception;
+
+/**
+ * Thrown when the BPN server closes the connection immediately without sending data.
+ *
+ * This typically indicates the server is busy processing other requests.
+ * Unlike a true timeout, this is a transient condition that may succeed on retry.
+ */
+class ImmediateConnectionCloseException extends ApiClientException
+{
+}