How does a cart mixing product types (physical + digital + subscription) check out?

A single cart can mix product types, and at checkout each line follows its own type's workflow while the customer sees one order. A physical line goes into fulfilment and delivery; a digital line issues a secure download on payment; a subscription line starts its billing cycle; a service line captures its schedule. One checkout, one payment, one order — but mixed fulfilment paths…

A single cart can mix product types, and at checkout each line follows its own type's workflow while the customer sees one order. A physical line goes into fulfilment and delivery; a digital line issues a secure download on payment; a subscription line starts its billing cycle; a service line captures its schedule. One checkout, one payment, one order — but mixed fulfilment paths underneath. This is the practical proof of "one engine, any commerce": the customer doesn't separate their purchase by type, and the system doesn't make them.