Lovable — Travel planner (Minimal)

Build a Travel planner.

Brief: Trip timeline with places, day-by-day itinerary, budget tracker.

Variant: Minimal
Keep it single-purpose — landing + one interaction. No auth, no DB.

Technical constraints:
- Next.js 15 App Router + Tailwind + shadcn/ui.
- Supabase for data + auth (when required).
- TypeScript everywhere.
- Mobile-responsive out of the box.
- Dark mode via next-themes.
- Accessible: semantic HTML, visible focus, keyboard navigation.

Deliver:
- Database schema with RLS policies if data-bound.
- All pages with empty states, loading states, and error states.
- A seeded demo account so I can log in and see the full app without signing up.

If you can't fit everything in one pass, ship the core flow end-to-end first, then iterate.