Add import/export and update system

Implement CSV/JSON import and export for domains, notification groups and tags (with masking for sensitive channel data), including size/format validation, in-memory CSV building, and logging. Add tag transfer and bulk transfer actions (admin-only). Introduce a new update system: Add UpdateController and UpdateService, migration 025_add_update_system_v1.1.3.sql, and installer changes to include the new migration and version handling; provide endpoints to check, apply, rollback and configure updates. Update helpers and UI bits: add getUpdateBadgeInfo in LayoutHelper, update notification icons/redirects, and add getMaxUploadSize in ViewHelper. Misc: add NotificationGroup::findByName, tweak .gitignore backups path, and update related views and routes.

app/Views/layout/base.php

@@ -12,9 +12,12 @@ if ($userId) {
     $notificationData = \App\Helpers\LayoutHelper::getNotifications($userId);
     $recentNotifications = $notificationData['items'];
     $unreadNotifications = $notificationData['unread_count'];
+    // Update badge in top menu (admin only, uses cached update check data)
+    $updateBadge = \Core\Auth::isAdmin() ? \App\Helpers\LayoutHelper::getUpdateBadgeInfo() : ['show' => false, 'available' => false, 'label' => ''];
 } else {
     $recentNotifications = [];
     $unreadNotifications = 0;
+    $updateBadge = ['show' => false, 'available' => false, 'label' => ''];
 }
 
 // Get domain stats for sidebar (available on all pages)