v0.3.0

Pre-1.0 reminder: this is a MINOR release, and in this package a minor may
carry breaking changes. This one carries one behaviour change (see Changed);
no API was removed or renamed.

Added

• Chained walkthroughs (#2). WalkthroughDocument.next names the
  walkthrough to start when this one completes (skipping never chains).
  Give one <Walkthrough> a library with walkthroughs={[...docs]} and the
  next one starts in place; if next is not in the library it is handed over
  through the storage adapter to whichever <Walkthrough> has that id, already
  mounted on the page or mounted on a later one.
• The active walkthrough is controlled state: walkthrough +
  onWalkthroughChange, or uncontrolled with defaultWalkthrough.
  useWalkthrough() gains walkthrough (the active id) and
  start(at?, walkthrough?).
• Steps on another page. step.route + <Walkthrough onNavigate>: when
  a step starts and the host is elsewhere, onNavigate(step, { walkthrough, index }) is called once and the HOST navigates (Inertia's router.visit, its
  own page transition). The package never navigates and depends on no router.
  The card waits for the target to register on the new page, and the step's
  whenMissing policy is held off until the host has arrived. Pass
  currentRoute (compared by string equality) so the package knows where
  the host is; without it, window.location.pathname is read in an effect.
• Resume across navigation and reloads through a storage adapter, per the
  design record's 2026-09-22 decision: storage={{ load, save }}, where
  load() returns WalkthroughProgress | null (or a Promise of it) and
  save(progress | null) stores it. WalkthroughProgress is
  { walkthrough, step?, index }; resume finds the step by id first, so
  reordering steps does not resume on the wrong one. An optional subscribe
  lets a hand-over reach a <Walkthrough> already on the page. The default is
  createLocalStorageAdapter(key = "fancy-walkthrough"), which is SSR-safe
  (nothing touches window at import or render) and degrades to remembering
  nothing when storage is disabled or full.
• Events: walkthrough:chained { walkthrough, from, to } when one hands
  over to the next; walkthrough:resumed { walkthrough, step, index } instead
  of started when progress is read back (so started stays an honest
  denominator); walkthrough:completed now carries next when there is one.
• Handles: the card carries data-walkthrough-id (the active walkthrough)
  and, while the host is navigating to its page, data-walkthrough-navigating
  (the route).
• Types: WalkthroughStorage, WalkthroughProgress,
  WalkthroughNavigateContext.

Changed

• In-progress walkthroughs now persist to localStorage by default. A tour
  that was running when the page reloaded resumes on the step it was on.
  Finishing or skipping clears it. To keep 0.2's behaviour, pass
  storage={null}. Nothing else to do: id and steps are now optional
  (they may come from walkthroughs instead), which accepts everything that
  compiled before.
• Nothing runs or reports until the store has been read, so a resumed
  walkthrough does not first report started at defaultStep. With a sync
  store this happens in the mount effect, before anything is painted.