feat: refine flipbook start modes and UI behavior

src/DependencyInjection/FlipbookExtension.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Mummert\FlipbookBundle\DependencyInjection;
+
+use Symfony\Component\Config\FileLocator;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Extension\Extension;
+use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
+
+class FlipbookExtension extends Extension
+{
+    public function load(array $configs, ContainerBuilder $container): void
+    {
+        $loader = new YamlFileLoader($container, new FileLocator(__DIR__.'/../../config'));
+        $loader->load('services.yaml');
+    }
+}