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/sabberworm/php-css-parser/src/Comment/CommentContainer.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Comment;
+
+/**
+ * Provides a standard reusable implementation of `Commentable`.
+ *
+ * @internal
+ *
+ * @phpstan-require-implements Commentable
+ */
+trait CommentContainer
+{
+    /**
+     * @var list<Comment>
+     */
+    protected $comments = [];
+
+    /**
+     * @param list<Comment> $comments
+     */
+    public function addComments(array $comments): void
+    {
+        $this->comments = \array_merge($this->comments, $comments);
+    }
+
+    /**
+     * @return list<Comment>
+     */
+    public function getComments(): array
+    {
+        return $this->comments;
+    }
+
+    /**
+     * @param list<Comment> $comments
+     */
+    public function setComments(array $comments): void
+    {
+        $this->comments = $comments;
+    }
+}