feat(lesson24): Using an API — list & add Programs

[JoyBrown252]

What & Why

Implements Lesson 24 “Using an API”:

• Replace fake data with live data from the API.
• Add a page to create new Programs via POST.
• Wire up routing and small header style fix.

Changes

• Data fetching/mutations (React Query)
  • src/lib/api.ts: GET /programs, POST /programs (handles 201 with no JSON body)
• UI
  • src/components/ProgramList.tsx: lists programs from the API
  • src/pages/AddProgram.tsx: form to create a program; invalidates list and navigates home on success
  • src/main.tsx: Router + React Query providers; routes for / and /add
  • src/App.tsx: layout with <Header /> and <Outlet />
  • src/components/Header.tsx + Header.scss: small logo sizing + link to Add Program
• Config
  • .env: VITE_API_URL=http://localhost:4000

How to Run

1. API (port 4000)

   cd lesson_24/api
   npm install
   npm run dev
   # Server at http://localhost:4000
   # JSON list at http://localhost:4000/programs (root "/" will show "Cannot GET /" — that's expected)