Fix: Prevent backend from returning empty data when site_uuid is all

backend/routes/dashboard/tenantConfig.js

@@ -14,11 +14,10 @@ router.get('/tenant-config', async (req, res) => {
 
     if (isGlobalUser) {
       const requestedSiteUuid = req.headers['x-backone-site-uuid'];
-      if (requestedSiteUuid) {
+      if (requestedSiteUuid && requestedSiteUuid !== 'all') {
         siteUuid = requestedSiteUuid;
       }
     } else if (req.user?.site_uuid) {
-      // For TENANT_ADMIN or other isolated roles, they only see their own site branding
       siteUuid = req.user.site_uuid;
     }