2819786f91
- Extract IWizardDraftRepository interface for testability (NSubstitute cannot mock sealed classes; the codebase uses fake-style doubles instead). - Add step-transition, pool-slot, validation, cancel/back, and render-shape tests using FakeWizardDraftRepository and FakeWizardMessenger. - Fix wizard payload persistence bug: HandleCallbackAsync and HandleTextAsync now call SavePayload after ApplyChoice/ApplyText mutations, so subsequent LoadPayload calls see the user's progress. Previously, local WizardPayload mutations were discarded and the wizard reset on every step. - CommitCurrentPoolSlot now auto-creates a slot via EnsureCurrentPoolSlot when one is missing, so the PoolSlotCapacity → waitlist click is recoverable even if the user lands on the step without a slot.