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.

Dockerfile.dev

@@ -0,0 +1,13 @@
+FROM node:24-alpine
+RUN corepack enable
+WORKDIR /app
+
+# Install dependencies first for better layer caching.
+COPY package.json pnpm-lock.yaml ./
+RUN pnpm install --frozen-lockfile
+
+COPY . .
+
+ENV HOST=0.0.0.0
+EXPOSE 3000
+CMD ["pnpm", "dev"]