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/clock/ClockAwareTrait.php

@@ -0,0 +1,38 @@
+<?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\Clock;
+
+use Psr\Clock\ClockInterface;
+use Symfony\Contracts\Service\Attribute\Required;
+
+/**
+ * A trait to help write time-sensitive classes.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+trait ClockAwareTrait
+{
+    private readonly ClockInterface $clock;
+
+    #[Required]
+    public function setClock(ClockInterface $clock): void
+    {
+        $this->clock = $clock;
+    }
+
+    protected function now(): DatePoint
+    {
+        $now = ($this->clock ??= new Clock())->now();
+
+        return $now instanceof DatePoint ? $now : DatePoint::createFromInterface($now);
+    }
+}