Wire execute-phase to invoke transition.md inline when --auto flag or
workflow.auto_advance config is set, propagate --auto through transition
to next phase invocations, add config-get command to gsd-tools, and fix
broken "config get" calls to use hyphenated "config-get" subcommand.
Closes#344
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>