Setting Up the Data Layer

Right now, nothing in this app talks to the database. In this module you’ll
build the foundation everything else sits on:

• lib/db.ts — a single, reused Postgres connection pool
• lib/types.ts — the TypeScript shape of a Contact
• lib/contacts.ts — your first query function, getContacts
• lib/utils.ts — small presentation helpers (initials, alphabet grouping)
• The Home page, actually rendering contacts from the database

Since the starter has no sample data yet, you’ll insert a few test rows by
hand with psql so there’s something to see. (A proper, repeatable seed
script is its own feature — you’ll build that in Module 10.)

By the end of this module, the Home page will show real contacts, grouped
alphabetically, pulled live from Postgres.