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/psr/http-factory/src/UploadedFileFactoryInterface.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Psr\Http\Message;
+
+interface UploadedFileFactoryInterface
+{
+    /**
+     * Create a new uploaded file.
+     *
+     * If a size is not provided it will be determined by checking the size of
+     * the file.
+     *
+     * @see http://php.net/manual/features.file-upload.post-method.php
+     * @see http://php.net/manual/features.file-upload.errors.php
+     *
+     * @param StreamInterface $stream Underlying stream representing the
+     *     uploaded file content.
+     * @param int|null $size in bytes
+     * @param int $error PHP file upload error
+     * @param string|null $clientFilename Filename as provided by the client, if any.
+     * @param string|null $clientMediaType Media type as provided by the client, if any.
+     *
+     * @return UploadedFileInterface
+     *
+     * @throws \InvalidArgumentException If the file resource is not readable.
+     */
+    public function createUploadedFile(
+        StreamInterface $stream,
+        ?int $size = null,
+        int $error = \UPLOAD_ERR_OK,
+        ?string $clientFilename = null,
+        ?string $clientMediaType = null
+    ): UploadedFileInterface;
+}