chore: scaffold Nuxt 4 app with Postgres, tooling and health route

Nuxt 4 (app/ structure) + TypeScript, ESLint, Vitest + @nuxt/test-utils,
Drizzle + pg, a /api/health route with a DB ping, and a dev docker-compose
(app + Postgres). Verified: pnpm test, lint, and build pass; the built
server answers /api/health.

nuxt.config.ts

@@ -0,0 +1,6 @@
+// https://nuxt.com/docs/api/configuration/nuxt-config
+export default defineNuxtConfig({
+  compatibilityDate: '2025-07-15',
+  devtools: { enabled: true },
+  modules: ['@nuxt/eslint', '@nuxt/test-utils/module'],
+})