Add ValueGeneratedOnAdd to ViewerBattlePassProgress.Id and
ViewerBattlePassClaims.Id so Postgres generates IDENTITY values at
runtime. Regenerate AddBattlePass migration in-place to include the
IdentityByDefaultColumn annotations. Add IBattlePassRepository /
BattlePassRepository (season lookup + level-curve cache) and
IViewerBattlePassRepository / ViewerBattlePassRepository
(get-or-create progress, claim reads/writes).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>