eugenp/tutorials ? reverse-engineered prompt

Build me a simple Spring Boot 3 tutorial module in this repo that shows a small real world example from start to finish.

I want it to be easy to run, easy to understand, and matched to the style of the existing tutorials. Include a basic web endpoint, a service layer, and a couple of tests so someone can see how it works and verify it quickly. If there is a good place for an integration test or a simple data example, add that too.

Make sure the app starts cleanly with the usual Maven commands from the module folder, and keep the code clear and minimal so it feels like a teaching example rather than a full product. If you need to check the latest Spring Boot 3 docs online for anything small, go ahead.