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/CacheWarmer/CacheWarmer.php

@@ -0,0 +1,32 @@
+<?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\CacheWarmer;
+
+/**
+ * Abstract cache warmer that knows how to write a file to the cache.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+abstract class CacheWarmer implements CacheWarmerInterface
+{
+    protected function writeCacheFile(string $file, $content): void
+    {
+        $tmpFile = @tempnam(\dirname($file), basename($file));
+        if (false !== @file_put_contents($tmpFile, $content) && @rename($tmpFile, $file)) {
+            @chmod($file, 0o666 & ~umask());
+
+            return;
+        }
+
+        throw new \RuntimeException(\sprintf('Failed to write cache file "%s".', $file));
+    }
+}