feat(sidebar): show user info with three-state UI (guest/member/vip)

Sidebar screen now primarily displays user-related information
and derives three render states from loginStatus + currentUser.isVip:

- guest (notLoggedIn): welcome panel + Sign in / Sign up entries
- member (logged in, no VIP): user info card + Get VIP CTA + Log out
- vip (logged in, VIP): user info card with VIP badge + Manage VIP CTA
  + Log out

Adds UserView.isVip (default false), patches user-machine.toView()
to populate it, and introduces three presentational components
(GuestPanel, UserInfoCard, VipCta) co-located under src/app/sidebar.

Preserves existing UserInit + logout-redirect behavior.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/app/sidebar/components/index.ts

@@ -2,4 +2,7 @@
  * @file Automatically generated by barrelsby.
  */
 
+export * from "./guest-panel";
 export * from "./sidebar-screen";
+export * from "./user-info-card";
+export * from "./vip-cta";