### Reason/Context Verify the Order Service's async API contract and event-driven flows. Inspired by steps in the Java Spring demo: [Step 5: Write async tests](https://github.com/microcks/microcks-testcontainers-java-spring-demo/blob/main/step-5-write-async-tests.md) ### Description - Implement integration tests for async endpoints and event flows. - Validate async contract with Microcks. - Document test cases and results (step5). ### Implementation ideas _No response_