/** Mirrors the `session.status` delta: a session is held while its last status event said
 *  running:true AND backgroundRunning:true; any other status event clears it.
 *
 *  Also carries the hold's CHANNEL and its abort handle, because the Stop path needs both. Stop
 *  (`sessions.cancel` → cancelChannelRuns) is channel-keyed and used to look only at
 *  `runningExecutions` — but a bg-held session has already left that registry (the execution is
 *  torn down BEFORE the hold is installed), so Stop found nothing and silently did nothing while
 *  the UI still showed the button. The channel index gives the channel-keyed cancel path a way to
 *  find the hold, and the abort handle lets it seal the hold immediately. */
export declare class BgHeldSessions {
    private held;
    private aborts;
    /** Feed every `session.status` event through this (wired to the bus in entry/app.ts). */
    onSessionStatus(e: {
        sessionId: string;
        channel?: string;
        running: boolean;
        backgroundRunning?: boolean;
    }): void;
    /** True while the session's foreground turn is over but a background task still holds it. */
    has(sessionId: string): boolean;
    /** Sessions currently bg-held on a channel — the reverse lookup the channel-keyed Stop path
     *  needs (`cancelChannelRuns`). Empty for an unheld/unknown channel. */
    sessionsOnChannel(channel: string): string[];
    /** Register the hold's abort (seal) handle — called by the hold itself via agent-runner. */
    setAbort(sessionId: string, abort: () => void): void;
    /** Fire the registered abort once (Stop during a bg hold). Returns false when the session has
     *  no live hold. Single-fire: the handle is dropped before invoking, and the seal's own
     *  `running:false` publish clears the rest of the entry through `onSessionStatus`. */
    abort(sessionId: string): boolean;
    /** Empty the registry (tests). */
    clear(): void;
}
/** Singleton instance (one server process = one registry). */
export declare const bgHeldSessions: BgHeldSessions;