/**
 * Create a SHA-256 hash of the given content (truncated to 16 characters)
 * 创建给定内容的 SHA-256 哈希（截断为 16 个字符）
 */
export declare function createContentHash(content: string): string;
/**
 * Check if a hash already exists in the cache (for duplicate detection)
 * 检查哈希是否已存在于缓存中（用于重复检测）
 */
export declare function isDuplicateByHash(hash: string, cache: Set<string>): boolean;