Set up the foundational Spring Boot project structure:
- Root POM with web, security, JPA, Flyway, validation, AOP, actuator
- PostgreSQL + Testcontainers for test infrastructure
- Application YAML configs for default, dev, and test profiles
- Maven wrapper (3.9.9) for reproducible builds
- .gitignore for Maven/IDE/OS artifacts
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>