/**
 * @file Stub-directory creation + permission audit. The IPC directory is
 *   created with 0o700 so other users can't read or plant files; on POSIX we
 *   also verify ownership and permission bits before any write, since a
 *   pre-existing directory could belong to a different user or have permissive
 *   modes inherited from umask.
 */
/**
 * Ensure IPC directory exists for stub file creation. Uses restrictive (0o700)
 * permissions so other users cannot read or write stub files. On POSIX, after
 * `mkdir` we verify the directory is owned by the current user and not
 * world/group-writable — protects against a prior local attacker pre-creating
 * `.socket-ipc/<app>/` with permissive modes and planting symlinks for stub
 * filenames. Throws if the directory fails the check.
 *
 * @internal
 */
export declare function ensureIpcDirectory(filePath: string): Promise<void>;
