/** Prefix of every computer-use screenshot fallback directory created under the OS temp dir. */
export declare const SCREENSHOT_FALLBACK_DIR_PREFIX = "gjc-computer-screenshots-";
/** Lazy-arm marker: called when the first screenshot fallback dir is created this process. */
export declare function markScreenshotFallbackDirCreatedForGc(): void;
/** Whether any screenshot fallback dir has been created this process (GC lazy-arm gate). */
export declare function hasCreatedScreenshotFallbackDir(): boolean;
/** Test-only: reset the lazy-arm marker between cases. */
export declare function resetScreenshotFallbackGcForTest(): void;
export interface ScreenshotGcOptions {
    now: () => number;
    staleMs: number;
    /** Base dir to scan; defaults to os.tmpdir(). Injectable for tests. */
    tmpDir?: string;
}
/**
 * Disk-only GC for stale computer-use screenshot fallback directories. Scans the temp dir for
 * `gjc-computer-screenshots-*` directories and removes those whose mtime is older than `staleMs`.
 * Never throws on a per-directory failure; the whole sweep is best-effort.
 */
export declare function cleanupStaleScreenshotFallbackDirs(options: ScreenshotGcOptions): Promise<{
    scanned: number;
    removed: number;
}>;