[emaarco]

Why

When the requested bike was out of stock, serviceTask_orderBike completed normally with bikeAvailable = false and no orderId. BPMN registers compensation for every completed activity, so when the back office then declined an alternative (alternativeFound = false) the order compensation callActivity_cancelBikeOrder ran with a missing orderId, the cancellation task failed and the instance ended in an incident; endEvent_contractCancelled was never reached. The same happened when the customer withdrew while userTask_clarifyAlternative was open. On top of that, nothing set the application to CANCELLED on the declined path.

Port of miragon-blueprints/cibseven-remote-example#31 (twin: miragon-blueprints/cibseven-process-engine-api-example#24). Issues are disabled in this repository, so there is no issue to close.

What

• Out-of-stock is a BPMN error on orderBike. New error Error_BikeUnavailable (bikeUnavailable) with an interrupting boundary event event_bikeUnavailable on serviceTask_orderBike leading to userTask_clarifyAlternative. gateway_bikeAvailable and the bikeAvailable variable are gone; orderBike flows straight to the parallel join. OrderBikeUseCase returns the OrderId and throws the new domain exception BikeUnavailableException; OrderBikeWorker translates it into BpmnErrorOccurred with the generated Errors.BIKE_UNAVAILABLE code. A task left through an error registers no compensation.
• The declined path reaches a terminal status. New service task serviceTask_confirmContractCancellation between event_triggerReversal and endEvent_contractCancelled, reusing the existing sendCancellationConfirmation topic. No new code.
• validateApplication is no longer a process step. The task, its error boundary event, Error_ApplicationInvalid, the worker, use case, service and ApplicationInvalidException are removed. The income check moved into LeasingApplication.receive, which throws IllegalArgumentException; the existing GlobalExceptionConfiguration answers it with a 400 problem detail.
• Diagram laid out with the bike order on the main axis; docs/assets/bike-leasing.png re-exported.
• Tests: process tests adapted, plus three new ones (declined alternative; withdrawal while clarifying; withdrawal after an accepted alternative cancels the one order exactly once). BikeUnavailableTransactionTest runs the out-of-stock order with the real services.
• Bruno: new scenarios 08-alternative-declined and 09-invalid-request.
• Typed process API regenerated with ./mvnw -pl service/app generate-sources.

Behaviour change to be aware of

• A leasing request with monthlyNetIncome <= 0 is now refused synchronously with 400 Invalid request and starts no process. Before, it was accepted with 200 and rejected by the process afterwards.
• The process variable bikeAvailable no longer exists; the model changed, so running instances of the old definition keep the old shape.
• @Transactional(noRollbackFor = ...) was deliberately not added to OrderBikeService: BikeUnavailableTransactionTest is green without it, because the @ProcessEngineWorker is not transactional and the service's rolled-back transaction does not enclose the engine call that reports the BPMN error.

How it was verified

• ./mvnw verify green locally (architecture, Checkstyle, unit, process, model validation, OpenAPI export; openapi/openapi.json unchanged).
• Diff-scoped PIT run locally on the changed classes: 13 of 14 mutations killed (93 %).
• npm run lint:bpmn clean.
• Exported PNG inspected: no overlaps.
• The Bruno scenarios were not run locally; the end-to-end job of this PR runs them.