We now expose ApplicationRuntime.of(ApplicationContext) to create a SpringBootApplicationRuntime as that's needed a lot in integration tests for runtime and observability components.
Moved the message population for the failure analyzer to the exception to be able to give more actionable feedback and educated users on the cause of the problem.
Adds ArchUnit as an explicit dependency to spring-modulith-runtime. Registers auto-configuration that throws an exception in case ArchUnit is missing from the classpath (as it is likely that it's declared as test scope dependency only) and a corresponding failure analyzer to give guidance on how to solve the problem.
We now use an AsyncTaskExecutor to bootstrap the ApplicationModules instance at startup asynchronously and - at the same time - do not block an explicit application shutdown. This also more idiomatic compared to using an ExecutorService directly.
Introduce Spring Modulith Actuator module to expose the application module structure as Spring Boot actuator. This required a Spring Modulith Runtime module to be extracted from the Spring Modulith Observability one. The former now contains the auto-configured ApplicationRuntime and ApplicationModulesRuntime bean instances to be able to bootstrap a ApplicationModules asynchronously on application startup. The actuator module then contains a Spring Boot @Endpoint implementation consuming the ApplicationModules to render JSON describing the application module structure.
