# App

A full-stack web app: React 19 frontend talking to a Spring Boot 3.4 REST API backed by PostgreSQL 17.
The frontend is a single-page app; it is not server-side rendered. This is not a monorepo — it is
one project with two build roots (`frontend/` and `backend/`) under a single git repo.

**Stack:** Vite 6 + React 19 (TypeScript, strict) — Biome 1.9 for format + lint — Vitest + Testing Library for frontend tests.
Spring Boot 3.4 (Java 21) — Maven — Google Java Format via Spotless — JUnit 5 + AssertJ for backend tests.
PostgreSQL 17 via Docker Compose; Flyway owns all schema changes.

## Rules

- **Never suppress warnings** with `@SuppressWarnings`, `biome-ignore`, or `// noinspection`; fix the root cause.
- **All HTTP responses are validated with Zod** on the frontend before touching any field; never access raw `response.data` directly.
- **Flyway owns the schema** — never `ALTER TABLE` manually or let Hibernate generate DDL. Write a migration instead.
- **Logs via SLF4J only** on the backend (`LOG_LEVEL` env var controls root level); do not use `System.out.println`.
- **Transaction boundaries live in the service layer**, not controllers or repositories. No `@Transactional` on `@RestController`.

## Running locally

```bash
docker compose up -d                              # PostgreSQL on :5432
mvn -f backend/pom.xml spring-boot:run           # backend on :8080
cd frontend && npm run dev                        # frontend on :5173 (proxies /api → :8080)
```

Verify everything at once: `mise run check` (requires mise; otherwise run the four commands in .mise.toml manually).