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/Models/NotificationGroup.php

@@ -98,5 +98,21 @@ class NotificationGroup extends Model
         $stmt->execute([$userId]);
         return $stmt->rowCount();
     }
+
+    /**
+     * Find a notification group by name
+     */
+    public function findByName(string $name, ?int $userId = null): ?array
+    {
+        if ($userId) {
+            $stmt = $this->db->prepare("SELECT * FROM notification_groups WHERE name = ? AND user_id = ? LIMIT 1");
+            $stmt->execute([$name, $userId]);
+        } else {
+            $stmt = $this->db->prepare("SELECT * FROM notification_groups WHERE name = ? LIMIT 1");
+            $stmt->execute([$name]);
+        }
+        $result = $stmt->fetch();
+        return $result ?: null;
+    }
 }