- Hardcode PostgreSQL connection URL to match docker service name 'postgres'
- Remove DB_URL environment variable dependency that was causing startup failures
- Keep username/password as environment variables for flexibility
- Remove default values from database environment variables
- Use POSTGRES_USERNAME/PASSWORD to match docker-compose.yaml
- Use DB_URL without default to ensure explicit configuration
- Add PostgreSQL datasource configuration for test and prod profiles
- Use environment-specific database URL, username, and password variables
- Set hibernate.ddl-auto=update for both profiles
- Enable SQL logging in test, disable in production
- Replace H2 in-memory database with PostgreSQL for consistency
