Move site content between installations as a package

System now exports a content package and imports one, by upload or from
var/pakete. Pages with their revisions, areas, menus, media, forms,
redirects, terms, translations, design and settings are replaced;
submissions, statistics, tasks, plugin state and service keys stay, and
accounts only come along when that is chosen explicitly. A backup comes
first, the site is in maintenance meanwhile, and every file and document
in the package is checked before anything is written.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/Controller/SystemController.php

@@ -11,6 +11,7 @@ use App\Ops\Backup;
 use App\Ops\Environment;
 use App\Ops\Installation;
 use App\Ops\OriginCheck;
+use App\Ops\SitePackage;
 use App\Ops\Updater;
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\HttpFoundation\JsonResponse;
@@ -28,7 +29,7 @@ use Symfony\Component\Routing\Attribute\Route;
  */
 final class SystemController extends AbstractController
 {
-    public function __construct(private Updater $updater, private Backup $backup, private ArchiveUpdate $archive, private Installation $installation, private string $adminPath, private string $databaseUrl, private string $mediaDirectory, private string $projectDir, private string $siteOrigin, private OriginCheck $originCheck, private HttpKernelInterface $kernel, private PageRepository $pages, private SiteSettings $settings)
+    public function __construct(private Updater $updater, private Backup $backup, private ArchiveUpdate $archive, private Installation $installation, private string $adminPath, private string $databaseUrl, private string $mediaDirectory, private string $projectDir, private string $siteOrigin, private OriginCheck $originCheck, private HttpKernelInterface $kernel, private PageRepository $pages, private SiteSettings $settings, private SitePackage $packages)
     {
     }
 
@@ -47,6 +48,9 @@ final class SystemController extends AbstractController
             'asked' => $request->query->getBoolean('pruefen'),
             'steps' => $request->getSession()->remove('update_steps') ?: [],
             'backups' => $this->backup->all(),
+            // Inhaltspakete (ADR 118): die per FTP abgelegten und die Grenze für Uploads.
+            'packages' => $this->packages->waiting(),
+            'uploadLimit' => $this->uploadLimit(),
             'adminPath' => $this->adminPath,
             // Der Weg ohne Git: das Releasearchiv. Auf geteiltem Hosting ist das der einzige.
             'archiveVersion' => $request->query->getBoolean('pruefen') ? $this->archive->updateAvailable() : null,
@@ -497,6 +501,23 @@ final class SystemController extends AbstractController
         return new Response($this->originCheck->token(), 200, ['Content-Type' => 'text/plain; charset=UTF-8', 'Cache-Control' => 'no-store', 'X-Robots-Tag' => 'noindex']);
     }
 
+    /** Die kleinere der beiden PHP-Grenzen, die einen Upload begrenzen - so, wie sie in der php.ini steht. */
+    private function uploadLimit(): string
+    {
+        $bytes = static function (string $value): int {
+            $value = trim($value);
+            $number = (int) $value;
+
+            return match (strtolower(substr($value, -1))) {
+                'g' => $number * 1024 ** 3, 'm' => $number * 1024 ** 2, 'k' => $number * 1024, default => $number,
+            };
+        };
+        $limits = array_filter([$bytes((string) ini_get('upload_max_filesize')), $bytes((string) ini_get('post_max_size'))]);
+        $min = [] === $limits ? 0 : min($limits);
+
+        return 0 === $min ? 'unbegrenzt' : number_format($min / 1048576, 0, ',', '.').' MB';
+    }
+
     private function back(string $message, string $type = 'error'): Response
     {
         $this->addFlash($type, $message);