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/mime/Encoder/IdnAddressEncoder.php

@@ -0,0 +1,44 @@
+<?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\Mime\Encoder;
+
+/**
+ * An IDN email address encoder.
+ *
+ * Encodes the domain part of an address using IDN. This is compatible will all
+ * SMTP servers.
+ *
+ * Note: It leaves the local part as is. In case there are non-ASCII characters
+ * in the local part then it depends on the SMTP Server if this is supported.
+ *
+ * @author Christian Schmidt
+ */
+final class IdnAddressEncoder implements AddressEncoderInterface
+{
+    /**
+     * Encodes the domain part of an address using IDN.
+     */
+    public function encodeString(string $address): string
+    {
+        $i = strrpos($address, '@');
+        if (false !== $i) {
+            $local = substr($address, 0, $i);
+            $domain = substr($address, $i + 1);
+
+            if (preg_match('/[^\x00-\x7F]/', $domain)) {
+                $address = \sprintf('%s@%s', $local, idn_to_ascii($domain, \IDNA_DEFAULT | \IDNA_USE_STD3_RULES | \IDNA_CHECK_BIDI | \IDNA_CHECK_CONTEXTJ | \IDNA_NONTRANSITIONAL_TO_ASCII, \INTL_IDNA_VARIANT_UTS46));
+            }
+        }
+
+        return $address;
+    }
+}