عرض عملي: تغيير API كاسر يكشفه عقد

خطوة بخطوة

1. Show the consumer test in orders generating the contract against inventory.
2. Publish the contract and run provider verification: green.
3. Planned mistake: in inventory, rename available to quantity for "clarity".
4. Run the provider build: verification fails and names the missing field and the consumer.
5. Fix: keep available, add quantity, and plan the migration in two steps.
6. Run the property tests on the Order aggregate as a final check.