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/console/Helper/HelperSet.php

@@ -0,0 +1,74 @@
+<?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\Console\Helper;
+
+use Symfony\Component\Console\Exception\InvalidArgumentException;
+
+/**
+ * HelperSet represents a set of helpers to be used with a command.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @implements \IteratorAggregate<string, HelperInterface>
+ */
+class HelperSet implements \IteratorAggregate
+{
+    /** @var array<string, HelperInterface> */
+    private array $helpers = [];
+
+    /**
+     * @param HelperInterface[] $helpers
+     */
+    public function __construct(array $helpers = [])
+    {
+        foreach ($helpers as $alias => $helper) {
+            $this->set($helper, \is_int($alias) ? null : $alias);
+        }
+    }
+
+    public function set(HelperInterface $helper, ?string $alias = null): void
+    {
+        $this->helpers[$helper->getName()] = $helper;
+        if (null !== $alias) {
+            $this->helpers[$alias] = $helper;
+        }
+
+        $helper->setHelperSet($this);
+    }
+
+    /**
+     * Returns true if the helper if defined.
+     */
+    public function has(string $name): bool
+    {
+        return isset($this->helpers[$name]);
+    }
+
+    /**
+     * Gets a helper value.
+     *
+     * @throws InvalidArgumentException if the helper is not defined
+     */
+    public function get(string $name): HelperInterface
+    {
+        if (!$this->has($name)) {
+            throw new InvalidArgumentException(\sprintf('The helper "%s" is not defined.', $name));
+        }
+
+        return $this->helpers[$name];
+    }
+
+    public function getIterator(): \Traversable
+    {
+        return new \ArrayIterator($this->helpers);
+    }
+}