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/flysystem/src/UnableToMoveFile.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace League\Flysystem;
+
+use RuntimeException;
+use Throwable;
+
+final class UnableToMoveFile extends RuntimeException implements FilesystemOperationFailed
+{
+    /**
+     * @var string
+     */
+    private $source;
+
+    /**
+     * @var string
+     */
+    private $destination;
+
+    public static function sourceAndDestinationAreTheSame(string $source, string $destination): UnableToMoveFile
+    {
+        return UnableToMoveFile::because('Source and destination are the same', $source, $destination);
+    }
+
+    public function source(): string
+    {
+        return $this->source;
+    }
+
+    public function destination(): string
+    {
+        return $this->destination;
+    }
+
+    public static function fromLocationTo(
+        string $sourcePath,
+        string $destinationPath,
+        ?Throwable $previous = null
+    ): UnableToMoveFile {
+        $message = $previous?->getMessage() ?? "Unable to move file from $sourcePath to $destinationPath";
+        $e = new static($message, 0, $previous);
+        $e->source = $sourcePath;
+        $e->destination = $destinationPath;
+
+        return $e;
+    }
+
+    public static function because(
+        string $reason,
+        string $sourcePath,
+        string $destinationPath,
+    ): UnableToMoveFile {
+        $message = "Unable to move file from $sourcePath to $destinationPath, because $reason";
+        $e = new static($message);
+        $e->source = $sourcePath;
+        $e->destination = $destinationPath;
+
+        return $e;
+    }
+
+    public function operation(): string
+    {
+        return FilesystemOperationFailed::OPERATION_MOVE;
+    }
+}