/**
 * Single-line stderr spinner for the non-interactive surface (06-ONESHOT §3).
 *
 * Active only when `err` is a TTY. The line is rewritten with `\r` and cleared
 * with `\r\x1b[K` before any other write, so stdout and stderr never interleave
 * mid-line. `clear()` is safe to call when inactive or already cleared.
 */
export interface StreamSpinnerOptions {
    readonly err: NodeJS.WritableStream & {
        isTTY?: boolean | undefined;
    };
    readonly columns: number;
    readonly unicode: boolean;
    readonly enabled?: boolean | undefined;
}
export declare class StreamSpinner {
    private readonly options;
    private readonly frames;
    private readonly active;
    private frame;
    private label;
    private painted;
    constructor(options: StreamSpinnerOptions);
    get isActive(): boolean;
    /** Paint (or repaint) the status line; a new label advances the frame. */
    tick(label: string): void;
    clear(): void;
}