/**
 * Returns the current network connectivity status.
 * Updates reactively on online/offline events.
 *
 * @returns {boolean} Whether the browser is currently online
 *
 * @example
 * const online = useOnline();
 * <Badge variant={online ? 'default' : 'destructive'}>
 *   {online ? 'Connected' : 'Offline'}
 * </Badge>
 */
export declare function useOnline(): boolean;