/**
 * Run `operation` exclusively for the given store key. Subsequent calls with
 * the same key wait until the in-flight operation settles (regardless of
 * success or failure).
 */
export declare function withLock<T>(key: string, operation: () => Promise<T>): Promise<T>;
/**
 * Write `data` to `path` atomically:
 *   1. Ensure the parent directory exists
 *   2. Write to a temp file with a random suffix
 *   3. Rename onto the final path (single syscall, atomic on POSIX)
 *
 * Renames are inherently atomic at the FS level, so a partial write or a
 * crash between writeFile and rename never leaves the destination in a
 * corrupt state — it's either the old contents or the fully-new contents.
 */
export declare function writeAtomically(path: string, data: string | Buffer): Promise<void>;