Add domain model (GameResult, GameSession, GameId, GameStore, GameMapper), DTOs, JacksonConfig, and GameResource REST endpoints with QuarkusTest coverage. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Introduces the backcore Quarkus REST module with build configuration, application.yml, and a smoke test confirming Quarkus boots successfully. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>