export interface State {
    version: 1;
    fallback: {
        enabled: boolean;
        autoEngaged: boolean;
    };
    /** Email pending restore from an interrupted `--as` session, or
     *  undefined when no restore is queued. */
    pendingRestore?: string;
    /** Snapshot of "last account routed to per emailDomain". Used by
     *  project-aware routing to pick deterministically when a
     *  `.claude-switch` constraint matches multiple saved accounts. Keyed
     *  by the lower-cased domain (`acme.com`), value is the chosen email.
     *  Optional — older state files predate the field; resolver tolerates
     *  an empty object. */
    lastUsedByDomain?: Record<string, string>;
}
/** Read the current state, migrating from legacy marker files if needed.
 *  Migration runs at most once — once `state.json` exists, the legacy
 *  files are ignored even if they reappear (a stray marker can't override
 *  the state we already trust). */
export declare function readState(accountsDirPath: string): State;
/** Apply a partial update INSIDE the caller's existing `withLock`. Use
 *  this when the surrounding code already holds the accounts-dir lock
 *  (passthrough's atomic snapshot, switcher's atomic switch+flip). */
export declare function updateStateInLock(accountsDirPath: string, patch: (state: State) => State): State;
/** Apply a partial update — acquires the lock first. Use from contexts
 *  with no surrounding `withLock` (CLI command handlers, settings UI). */
export declare function updateState(accountsDirPath: string, patch: (state: State) => State): State;