- Refactor setJavaDefault to delegate shared output/env logic to
setJavaEnvironment, avoiding duplication between the two.
- Document that set-default applies to all JDKs in a multiline
java-version, and that installed JDKs remain registered in Maven
toolchains regardless of set-default.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>