flowable/flowable-engine — reverse-engineered prompt

Build me a compact Java workflow and business process management platform like Flowable.

I want developers to define business processes, start them from code or an API, track where each process is, assign human tasks for approvals, run automated service steps, and evaluate decision rules. It should support BPMN style workflows, case style work, and simple DMN style rules. Make it usable embedded inside a Java or Spring application, but also runnable as its own server with REST endpoints.

Please target JDK 17 or newer, keep it efficient and practical, and include enough examples so someone can run a sample approval process locally and see tasks move from start to finish. Add clear setup instructions, basic tests, and a simple way to package or run it locally, ideally with Docker if that fits. Look up current docs online if you need to.