mkconcore cannot build generated Java studies #571

Java works when compiled from the repo root, but mkconcore.py does not copy everything required by generated Java studies.

For local studies, it copies concore.java without ConcoreJavaRuntimeCore.java or JeroMQ, so compilation fails. In Docker mode, .java is not handled and falls back to Dockerfile.m.

Reproduce

python mkconcore.py example/java_e2e/java_e2e.graphml . /tmp/java-study posix

The generated Java node fails to compile because ConcoreJavaRuntimeCore is missing.

Docker mode selects the wrong Dockerfile:

python mkconcore.py example/java_e2e/java_e2e.graphml . /tmp/java-docker docker

assuming .m extension for Dockerfile

Expected:
Generated local and Docker studies should include everything needed to build and run Java nodes.

Actual:
Local Java studies are missing runtime dependencies, while Docker generation selects the Octave image.