Stand: SMTP-Test, Admin-Mail-Tab, Notifiable-Fix, Lazy-Quill

- Fix: Notifiable-Trait zum User-Model hinzugefuegt (behebt notify()-500er)
- Installer: SMTP-Verbindungstest mit EsmtpTransport + Ueberspringen-Link
- Admin: Neuer E-Mail-Tab mit SMTP-Konfiguration + Verbindungstest
- Admin: Lazy Quill-Initialisierung (nur sichtbare Locale wird geladen)
- Uebersetzungen: 17 neue Mail-Keys in allen 6 Sprachen

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

vendor/symfony/http-kernel/Controller/ControllerResolverInterface.php

@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\Controller;
+
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * A ControllerResolverInterface implementation knows how to determine the
+ * controller to execute based on a Request object.
+ *
+ * A Controller can be any valid PHP callable.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+interface ControllerResolverInterface
+{
+    /**
+     * Returns the Controller instance associated with a Request.
+     *
+     * As several resolvers can exist for a single application, a resolver must
+     * return false when it is not able to determine the controller.
+     *
+     * The resolver must only throw an exception when it should be able to load a
+     * controller but cannot because of some errors made by the developer.
+     *
+     * @return callable|false A PHP callable representing the Controller,
+     *                        or false if this resolver is not able to determine the controller
+     *
+     * @throws \LogicException If a controller was found based on the request but it is not callable
+     */
+    public function getController(Request $request): callable|false;
+}