Javablog.com Kafka Integration

In the latest commit, I added an adapter-kafka into my javablog.com/services project. Apache Kafka will implement the TranslationPort in the hexagonal architecture that is evolving in the javablog API. There are two Topics: translation.requests and translation.responses. Javablog.com will write to the requests and Polybit.ch will read the message. Polybit.ch will write to the responses with a completed translation from an LLM. Javablog.com will poll the translation.responses topic every few minutes and persist the translations as they come in.

I put in a lot of effort to get the secure remote Apache Kafka connection stabilized using Keycloak for SASL_SSL/OAUTHBEARER tokens. Since Apache Kafka will live in the same docker network as the JavaBlog.com API, it uses plaintext 9092. Pretty neat.