TourDrive:
    | ImportAdventureDrive
    | ActivateSceneDrive
    | StartCombatDrive
    | RollInitiativeDrive
    | AdvanceTurnDrive
    | SetTargetDrive
    | ClearTargetDrive

A single drive action declared on a step. The discriminated kind selects the shape; SohlTour executes each in the order declared, awaiting one before the next.