Direct custom ResourceArtifact creation for the MAMS tutorial.
Requires Java 17+, Maven, ASTRA 2.6.1 and MAMS 2.4.1.
Run: mvn clean compile astra:run
Read: curl -i -H 'Accept: application/json' http://localhost:9000/main/counter
Expected body: {"value":42}; PUT is refused with HTTP 405.
Stop with Ctrl+C. The custom handler returns JSON only and does not implement
Accept negotiation or the Java-Types active decision protocol.
