/**
 * Tries to unescape the content from either key or value of a property.
 *
 * Uses a single-pass, segment-based approach with `charCodeAt()` instead of
 * regex. Scans for backslashes, flushes literal text in bulk via `slice()`,
 * and only builds new characters for actual escape sequences.
 *
 * @param content - The content to unescape.
 *
 * @returns The unescaped content.
 *
 * @throws Error if malformed escaped unicode characters are present.
 */
export declare const unescapeContent: (content: string) => string;