cc40e2d2e8
Implements the class-selection and card-pick turns for the Take Two arena draft: - ChooseClassAsync validates class is offered, locks ClassId, generates first pick set via pool - ChooseCardAsync appends the two picked cards, advances SelectTurn 1–15, completes draft at turn 15 - 6 new tests covering happy paths and all error codes (class_not_offered, invalid_state, invalid_selection) Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>