fix: handle stdio properly

src/ExitStatus.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nih\CommandBuilder;
+
+final class ExitStatus
+{
+    public function __construct(
+        public readonly int $code,
+    ) {
+    }
+
+    public function success(): bool
+    {
+        return $this->code === 0;
+    }
+}