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/console/Command/SignalableCommandInterface.php

@@ -0,0 +1,36 @@
+<?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\Console\Command;
+
+/**
+ * Interface for command reacting to signal.
+ *
+ * @author Grégoire Pineau <lyrixx@lyrix.info>
+ */
+interface SignalableCommandInterface
+{
+    /**
+     * Returns the list of signals to subscribe.
+     *
+     * @return list<\SIG*>
+     *
+     * @see https://php.net/pcntl.constants for signals
+     */
+    public function getSubscribedSignals(): array;
+
+    /**
+     * The method will be called when the application is signaled.
+     *
+     * @return int|false The exit code to return or false to continue the normal execution
+     */
+    public function handleSignal(int $signal, int|false $previousExitCode = 0): int|false;
+}