Component/runtime specs (*.nuxt.spec.ts) run in the Nuxt environment; all
other specs run in a plain node environment where node_modules stay external,
so native CJS deps like `pg` load correctly (the Nuxt runtime inlines them and
breaks pg's internal `class … extends Pool`). Adds tests/helpers/db.ts, which
spins up and migrates a dedicated test database for repository integration
tests, and renames the board spec to the .nuxt suffix.
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.