/**
 * Serialized, crash-atomic persistence for the small user-level JSON files
 * under the DSH home (statusline.json, theme.json). Two guarantees the bare
 * floating `writeFile` path could not give:
 *
 * 1. Every save is appended to ONE chain, so rapid consecutive edits land
 *    in submission order and the last snapshot is the one on disk (parallel
 *    floating writes let an older snapshot finish last and win).
 * 2. Each write goes to a sibling temp file first and is renamed into
 *    place, so a crash mid-write can never leave a half-written JSON
 *    document behind.
 *
 * The chain itself never rejects: a failed write is reported to that
 * save's caller while later saves keep their turn.
 *
 * @module @deepseek-ai/dsh-code/settings-file
 */
/**
 * Write one file atomically: create the parent directory, write to a
 * uniquely named temp file, and rename it into place. A crash midway
 * can never leave a half-written document behind. Unique temp names
 * keep concurrent writers (two terminals, two chains in one process)
 * from sharing one temp path.
 */
export declare function writeFileAtomically(path: string, text: string): Promise<void>;
/** The serialized persistence surface; flush() is handed to the quit sequence. */
export interface UserSettingsPersistence {
    /**
     * Queue one file snapshot. Resolves when the chain reaches (and renames)
     * it; rejects only to THIS caller when its own write failed.
     */
    save(path: string, text: string): Promise<void>;
    /** Wait for every queued write; safe to call repeatedly. */
    flush(): Promise<void>;
}
/**
 * Create the shared settings-write chain. One instance per process keeps
 * every user-level JSON file mutually serialized.
 * @returns the persistence handle.
 */
export declare function createUserSettingsPersistence(): UserSettingsPersistence;
/**
 * Read one user-level settings file as a plain object. The callers all treat a
 * missing file as "unset" and a corrupt one as "warn and fall back", so this
 * helper owns the one distinction they share: readable JSON that is not an
 * object is corruption, not an absent preference, and must not surface as a
 * cryptic property access on `null`.
 * @param path - absolute path of the settings file.
 * @returns the parsed object; the caller narrows each field itself.
 */
export declare function readSettingsObject(path: string): Record<string, unknown>;