Add guest/account auth flows, order tracking, and order history UI

- Wire up Better Auth (email/password + Google/Apple SSO) with a
  sign-in/sign-up UI, header account menu, and a basket that follows
  the signed-in-or-guest state.
- Give the order status page a vertical timeline per preparation step
  (with a distinct customer-facing name separate from the machine tag,
  a done/in-progress/queued/pending look, and a sonar-ping highlight on
  the active step), a formatted ETA (relative under 3h, absolute clock
  time beyond that), and Buy again / Get help / Cancel actions.
- Expand Pizza's recipe into 6 steps across a shared prep station and
  the existing oven/assembly stations, with matching schema, seed, and
  domain changes plus updated/added test coverage.
- Add an Orders list (account orders via session, guest orders via a
  locally remembered access-token list) with a shared getOrdersForCustomer
  domain summary, and remember a guest's name/contact after their first
  order so checkout doesn't ask again.
- Improve page transitions with the View Transitions API: a shared
  element morph between an order card and its detail page, a stable
  (non-jumping) header across navigations, and reduced-motion handling.
- Add a Ghost Kitchen wordmark (Space Grotesk, faded "Ghost", ghost
  icon standing in for the "o") and shrink the basket icon to match
  the rest of the header controls.
- Add a run-ghost-kitchen agent skill documenting local setup, the
  dev-server driver, and the gotchas hit along the way.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.env.example

@@ -1 +1,10 @@
 DATABASE_URL=postgres://postgres:postgres@localhost:5433/ghost_kitchen
+BETTER_AUTH_URL=http://localhost:3000
+BETTER_AUTH_SECRET=
+
+# Optional: enables "Continue with Google" / "Continue with Apple" on the
+# sign-in and sign-up pages. Leave unset to fall back to email/password only.
+GOOGLE_CLIENT_ID=
+GOOGLE_CLIENT_SECRET=
+APPLE_CLIENT_ID=
+APPLE_CLIENT_SECRET=