Carry the publisher owner's parsed reason through the launch error and public CLI/MCP projection without inventing a helper exit. Share exact unsupported launch checks between package and real-Linux verification, and keep foreign fixture rejection independent of vendor network availability. Co-authored-by: Kaoru0822 <208281322+kaoru0822-kitauji@users.noreply.github.com> Co-authored-by: gensokyo-dev <342580529+gensokyo-dev@users.noreply.github.com>