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/translation/Loader/PhpFileLoader.php

@@ -0,0 +1,35 @@
+<?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\Translation\Loader;
+
+/**
+ * PhpFileLoader loads translations from PHP files returning an array of translations.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class PhpFileLoader extends FileLoader
+{
+    private static ?array $cache = [];
+
+    protected function loadResource(string $resource): array
+    {
+        if ([] === self::$cache && \function_exists('opcache_invalidate') && filter_var(\ini_get('opcache.enable'), \FILTER_VALIDATE_BOOL) && (!\in_array(\PHP_SAPI, ['cli', 'phpdbg', 'embed'], true) || filter_var(\ini_get('opcache.enable_cli'), \FILTER_VALIDATE_BOOL))) {
+            self::$cache = null;
+        }
+
+        if (null === self::$cache) {
+            return require $resource;
+        }
+
+        return self::$cache[$resource] ??= require $resource;
+    }
+}