/**
 * Pure surface-key helpers (no map reads). Surface keys originate from artifact
 * filenames and flow into the PR-comment summary — strip Markdown/HTML control
 * characters so they cannot inject a link, image, or table into that bot comment.
 */
export declare const safeKey: (s: string) => string;
export declare const surfaceBase: (s: string) => string;
export declare const surfaceWidth: (s: string) => number;
/**
 * Capture keys name map files under the output directory. Reject anything that
 * is not a single relative path segment: separators, traversal, drive prefixes,
 * absolute forms, NUL, and empty keys. Uniqueness alone is not filesystem-safe.
 */
export declare function assertSafeCaptureKey(key: string): string;
/**
 * Build the map/screenshot stem inside `outputDir`. Always validates the surface
 * key first so hostile keys cannot escape the output directory.
 */
export declare function captureArtifactStem(outputDir: string, surfaceKey: string, width: number | string): string;
/**
 * Product surface base for counting: authoritative `metadata.surfaceKey` when the
 * caller supplies it, otherwise strip a trailing `@width` from the capture key
 * (older captures without metadata).
 */
export declare function productSurfaceBase(captureKey: string, authoringSurfaceKey?: string): string;
export declare function pushSurfaceWidth(byBase: Map<string, number[]>, base: string, surface: string): void;
export declare function renderSurfaceGroups(byBase: Map<string, number[]>): string;
/** "landing @ 1280, 1080, 390 · landing-nav-open @ 1080" from the surface keys. */
export declare function formatSurfaceList(surfaces: string[]): string;
/** Unique product surface bases and capture keys among surfaces that carry a grouped change. */
export declare function countChangedSurfaceScope(groups: Array<{
    surfaces: string[];
}>, surfaceKeyOf?: (captureKey: string) => string | undefined): {
    bases: number;
    variants: number;
};
/** Unique product surface bases across a set of capture keys (e.g. every map in a dir). */
export declare function countCapturedSurfaceBases(captureKeys: Iterable<string>, surfaceKeyOf?: (captureKey: string) => string | undefined): number;
/** Headline / summary phrasing for changed-surface counts (bases first; variants when wider). */
export declare function formatChangedSurfaceScope(bases: number, variants: number): string;