/**
 * Reactive auth state with authenticate/deauthenticate actions.
 * Syncs across all tabs via BroadcastChannel. No-ops while the socket is null.
 *
 * @example
 * function Header() {
 *   const { isAuthenticated, deauthenticate } = useSocketAuth();
 *   return isAuthenticated
 *     ? <button onClick={deauthenticate}>Logout</button>
 *     : <Link to="/login">Login</Link>;
 * }
 */
export declare function useSocketAuth(): {
    isAuthenticated: boolean;
    authenticate: (token: string) => void;
    deauthenticate: () => void;
};