A minimal full‑stack audio library explorer. Backend serves a PostgreSQL‑backed song catalog and streams files from a local backend/db/Music folder; frontend (CRA React) lists, filters, and plays tracks via simple endpoints.

.
├─ backend/            # Express API + PostgreSQL access
│  ├─ db/
│  │  ├─ db.js        # Pool + schema init + scanner
│  │  └─ Music/       # Place .mp3 files here (ignored in git)
│  ├─ server.js       # API routes and file streaming
│  ├─ package.json
│  └─ .env.example    # Copy to .env and fill values
├─ frontend/
│  └─ myapp/          # React app (CRA)
│     ├─ src/
│     ├─ public/
│     └─ package.json
├─ .gitignore
└─ README.md

• Node.js LTS (>=18)
• PostgreSQL (>=13)

1. Backend
   • Copy env: cp backend/.env.example backend/.env (Windows: copy the file) and fill values
   • Install deps: cd backend && npm install
   • Run server: npm start (or node server.js) — defaults to http://localhost:5000
2. Frontend
   • Install deps: cd frontend/myapp && npm install
   • Start dev server: npm start — defaults to http://localhost:3000

Backend .env keys:

• PORT — API port (default 5000)
• CLIENT_ORIGIN — allowed CORS origin (e.g. http://localhost:3000)
• DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE, DB_PORT

• Backend: npm start
• Frontend: npm start, npm run build

Place .mp3 files in backend/db/Music/. On server start, the catalog is scanned and inserted into songs table (id, name, path). Large media are ignored by git; a .gitkeep preserves the folder.

• GET /api/songs — list songs { id, name, path }
• GET /api/songs/:id/file — stream file by id

• Use feature branches and conventional commit messages
• Keep secrets out of git; commit only .env.example