feat: overhaul groups management, remove global team_admin and isolate group administration

frontend/src/features/settings/UserSettingsView.tsx

@@ -236,8 +236,6 @@ export const UserSettingsView: React.FC<UserSettingsViewProps> = ({
   const roleBadgeLabel =
     currentUser.role === 'admin'
       ? 'Server-Admin'
-      : currentUser.role === 'team_admin'
-      ? 'Team-Admin'
       : 'Mitglied';
 
   return (