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/league/commonmark/src/Normalizer/UniqueSlugNormalizer.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the league/commonmark package.
+ *
+ * (c) Colin O'Dell <colinodell@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace League\CommonMark\Normalizer;
+
+// phpcs:disable Squiz.Strings.DoubleQuoteUsage.ContainsVar
+final class UniqueSlugNormalizer implements UniqueSlugNormalizerInterface
+{
+    private TextNormalizerInterface $innerNormalizer;
+    /** @var array<string, bool> */
+    private array $alreadyUsed = [];
+
+    public function __construct(TextNormalizerInterface $innerNormalizer)
+    {
+        $this->innerNormalizer = $innerNormalizer;
+    }
+
+    public function clearHistory(): void
+    {
+        $this->alreadyUsed = [];
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @psalm-allow-private-mutation
+     */
+    public function normalize(string $text, array $context = []): string
+    {
+        $normalized = $this->innerNormalizer->normalize($text, $context);
+
+        // If it's not unique, add an incremental number to the end until we get a unique version
+        if (\array_key_exists($normalized, $this->alreadyUsed)) {
+            $suffix = 0;
+            do {
+                ++$suffix;
+            } while (\array_key_exists("$normalized-$suffix", $this->alreadyUsed));
+
+            $normalized = "$normalized-$suffix";
+        }
+
+        $this->alreadyUsed[$normalized] = true;
+
+        return $normalized;
+    }
+}