/**
 * [WHO]: Provides SessionTreeController — session-tree navigation + branch summarization
 * [FROM]: Depends on session/compaction (generateBranchSummary), session-manager (BranchSummaryEntry),
 *         extensions-host (TreePreparation, SessionBeforeTreeResult), platform/abort-slot,
 *         and ./session-context (SessionTreeControllerContext)
 * [TO]: Consumed by core/runtime/agent-session.ts (constructs one, delegates navigateTree()/abortBranchSummary())
 * [HERE]: core/runtime/agent-session.ts split (AS10) — owns the branch-summary abort slot
 *
 * Extracted from AgentSession (AS10). Owns navigateTree() and the branch-summary cancellation
 * state. Unlike fork() (a session-identity change), navigateTree stays in the same session file
 * and moves the leaf. Session state is reached through SessionTreeControllerContext; behavior is
 * identical to the former AgentSession.navigateTree().
 */
import type { BranchSummaryEntry } from "../session/session-manager.js";
import type { SessionTreeControllerContext } from "./session-context.js";
export interface NavigateTreeOptions {
    summarize?: boolean;
    customInstructions?: string;
    replaceInstructions?: boolean;
    label?: string;
}
export interface NavigateTreeResult {
    editorText?: string;
    cancelled: boolean;
    aborted?: boolean;
    summaryEntry?: BranchSummaryEntry;
}
export declare class SessionTreeController {
    private readonly ctx;
    /** Cancellation slot for the in-flight branch summarization. */
    private readonly _slot;
    constructor(ctx: SessionTreeControllerContext);
    /** Cancel an in-progress branch summarization. */
    abortBranchSummary(): void;
    /**
     * Navigate to a different node in the session tree (stays in the same session file; moves the
     * leaf). Optionally summarizes the abandoned branch.
     */
    navigateTree(targetId: string, options?: NavigateTreeOptions): Promise<NavigateTreeResult>;
}