/**
 * Reconcile-pass diff over the layer IR (spec: "Reactivity — the watch
 * declaration"), shared by both front-ends (HU2): decides which narrow
 * `data:<id>` watch tokens fire and whether `layers` (added/removed/
 * visibility toggled) should. Reference equality only, matching the
 * "stable reference" discipline used throughout — a layer's `data` array
 * is the same reference across reconciles unless it genuinely reloaded.
 */
import type { LayerIR } from "./ir";
export interface LayerIRDiff {
    /** Layers whose `data` reference changed (or that are new) — fires `data:<id>` tokens. */
    changedDataIds: Set<string>;
    /** A layer was added/removed, toggled visibility, or changed its declarative filter — fires the `layers` token. */
    layersChanged: boolean;
}
export declare function diffLayerIRs(previous: ReadonlyMap<string, LayerIR>, next: ReadonlyMap<string, LayerIR>): LayerIRDiff;