/**
 * Creates a Git-delta based patch for transforming `base` into `updated`.
 * Format:
 * - 20 bytes: SHA-1(base)
 * - N bytes: Git delta payload
 * - 20 bytes: SHA-1(updated)
 */
export declare function createFilePatch(base: string, updated: string): Promise<Uint8Array>;
/**
 * Applies a patch created by `createFilePatch` and returns the updated string.
 */
export declare function applyFilePatch(base: string, patch: Uint8Array): Promise<string>;