/**
 * Watch the DOM for a target element's *resolution* changing — appearing (a lazily
 * rendered `data-guide` element) or disappearing (removed, or swapped out by a route
 * change). `onChange(next)` fires whenever `resolve()` returns a different element than
 * the previous call, coalesced to at most one resolve per animation frame so a burst of
 * unrelated mutations (e.g. a live table re-rendering rows) stays cheap.
 *
 * This complements {@link autoUpdate}, which only tracks the *position and size* of an
 * element that already exists — it cannot notice one that is not in the DOM yet, nor one
 * that has been removed. The Guide surfaces (tour bubble + hint) use this to re-anchor a
 * step whose target renders after the surface, and to fall back gracefully when a target
 * vanishes mid-flight.
 *
 * SSR / no-`MutationObserver` safe: returns a no-op disconnect when there is no DOM.
 *
 * @param resolve Returns the current target element (or `null` when unresolved).
 * @param onChange Called with the new element each time resolution flips.
 * @returns A disconnect function — call it on cleanup.
 */
export declare function observeTargetResolution(resolve: () => HTMLElement | null, onChange: (next: HTMLElement | null) => void): () => void;