Flyenzo Flight Booking Platform Enhancements

I have already taken Flyenzo from concept to a working end-to-end flight booking flow using Next.js 16 with the App Router, TypeScript, Neon Postgres via Drizzle ORM, Redis, Stripe, and Clerk auth. Search, Stripe Checkout, PNR generation, printable e-tickets, and online check-in are live and stable.

What I need now is focused, production-ready work on three areas that matter most to travellers and to the business:

1. Live cabin map
The current map renders seats and respects my Redis Lua seat-lock script, but I want smoother real-time updates across multiple sessions, optimistic UI during seat selection, and graceful fallback in local development when Redis is not available.

2. Ancillary add-ons
Meal options, lounge access, and priority boarding must be selectable in-flow, priced dynamically, and passed to Stripe as separate line items so they appear clearly on the receipt. The code needs to remain idempotent with the existing webhook logic.

3. Cancellation refunds
Passengers can already cancel, but the refund pipeline is still manual. I need automated pro-rating against fare rules, instant Stripe refund creation, and a clear audit trail stored in Postgres.

Tech context and constraints
• Next.js 16 App Router, React Server Components, server actions
• TypeScript strict mode throughout the mono-repo
• Drizzle migration system already in place
• Redis seat locks use atomic Lua scripts with a 10-minute TTL
• Stripe API v2023-10-16 and existing webhook endpoint
• Clerk for authentication and session management
• pgvector powers a destination-matching concierge feature and must stay untouched

Acceptance criteria
• Selecting or changing a seat on the live cabin map instantly reflects on all concurrent sessions without race conditions.
• Add-ons (meal, lounge, priority) appear in the booking UI, are saved to Postgres, and are reconciled as separate Stripe charges on both checkout and webhook confirmation.
• Cancelling a booking triggers an automatic, rule-compliant refund and writes a detailed refund record, visible in the admin dashboard.
• All new logic covered by unit tests and an end-to-end flow test using Playwright.
• Code style matches the existing ESLint and Prettier setup.

If you have deep experience in Next.js App Router, real-time state with Redis, strong TypeScript discipline, and proven Stripe integration skills, I want to hand you these next milestones so we can push Flyenzo toward public launch.