Event model direction

The sport-specific schema is not final until the team and stakeholder select the sport and approve its event vocabulary.

The model should distinguish competitions, seasons, competitors, fixtures, ordered event records, submission provenance, validation/review states, correction history, statistic definitions and versions, derived results, and dataset releases.

Every published statistic must be derived from accepted event records and remain traceable to its submission, events, and statistic-definition version. The executable migration history will live under database/migrations/.