/**
 * Decide how to split a filename for middle-truncation (head + fixed-length tail,
 * so the extension stays visible).
 *
 * Returns `null` when no split should happen — either the caller didn't ask for
 * a tail, or the filename is so short that splitting would produce visual noise
 * (we use a threshold of `tail + 3` characters, same as the React Truncate
 * component has used since it was introduced).
 */
export declare function splitFilenameForTruncation(filename: string, tail: number | undefined): {
    head: string;
    tail: string;
} | null;