/**
 * Most-recently-used ordering for overflow tab-switching, private to the
 * advanced overflow module.
 *
 * Keeps, per group, the group's panel ids ordered by last activation; the front
 * is the most recently activated. Component-scoped (one tracker per component) so
 * recency survives a group closing and a panel moving between groups. There is
 * no second consumer, so this deliberately stays a module-local model rather
 * than a shared core primitive.
 */
export declare class MruTracker {
    private readonly _byGroup;
    /**
     * Seed a group's recency list from its current tab order (front = first
     * tab). Called on group attach. Idempotent: re-seeding replaces the list,
     * but existing recency is preserved for ids already tracked so a re-attach
     * doesn't reset ordering.
     */
    attach(groupId: string, panelIds: readonly string[]): void;
    /** Drop a group's recency list, called when the group is removed. */
    detach(groupId: string): void;
    /**
     * Record an activation: move `panelId` to the front of `groupId`'s list.
     * The panel is first removed from every other group's list so a cross-group
     * move leaves the source list and enters the destination.
     */
    activate(groupId: string, panelId: string): void;
    /** Remove a panel from every group's list, called when a panel is closed. */
    remove(panelId: string): void;
    /**
     * The recency order (front = most recent) for a group, or an empty list
     * when the group is not tracked.
     */
    order(groupId: string): string[];
    /** Whether a group currently has a recency list. */
    has(groupId: string): boolean;
}