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.

tests/smoke.spec.ts

@@ -0,0 +1,7 @@
+import { describe, it, expect } from 'vitest'
+
+describe('smoke', () => {
+  it('runs the test suite', () => {
+    expect(true).toBe(true)
+  })
+})