MithunTechnologiesDevOps/Springboot-Mongo-Application ? reverse-engineered prompt

Build me a simple Spring Boot app that talks to MongoDB and can be packaged with Maven into a runnable jar.

I want the project to be easy to build locally with mvn clean package, then run in Docker with a Dockerfile and docker compose so the app and MongoDB start together. Please also include a basic Jenkins pipeline file for building the app and creating the image, since I want to be able to set up a simple CI flow later.

The app does not need to be fancy, but it should feel complete enough to run and test right away, with a couple of basic REST endpoints and whatever model and repository pieces are needed for MongoDB. If you need to check current Spring Boot or Docker setup details online, go ahead and do that. Keep it straightforward and runnable from the files in the repo.