Payout Account Model

Mirrors /vendor/stripe/account. Exposes derived helpers: needsBankAccount, isVerified, isVerificationPending — consumed by the wizard to auto-advance the step.

1. PayoutAccountModel.fromJson reads capabilities, requirements, charges_enabled, payouts_enabled.
2. Helpers compute readable booleans the wizard can branch on without reasoning about Stripe internals.

• Verification can move through pending → verified → pending again if Stripe requests another document.
• needsBankAccount stays true even after the user adds a card-funded source — only a real bank routing/account number satisfies it.

• lib/src/features/seller/bank_account/models/payout_account_model.dart

Helpers exist precisely so the wizard doesn't reach into Stripe-shaped maps; keep them stable as the API evolves.