/**
 * Masked secret editor state (INPUT-009, V2-046).
 *
 * The raw value never surfaces through the normal getters, string coercion,
 * or JSON serialization used everywhere else in the app (transcript,
 * history, logs) — only `reveal()` returns it, so a secret can only leave
 * this buffer through the one call site that explicitly asks for it.
 */
export declare class SecretBuffer {
    private value;
    insert(text: string, cursorOffset: number): number;
    deleteBackward(cursorOffset: number): number;
    clear(): void;
    get length(): number;
    masked(): string;
    /** The only sanctioned way to read the plaintext back out. */
    reveal(): string;
    toString(): string;
    toJSON(): string;
}