WiX warns it only supports Windows and errored on the Linux runner (WIX0389).
Split the pipeline: ubuntu-host builds the binaries + image + release and passes
the windows/amd64 binary as an artifact; a new msi job on windows-host wraps it
into the MSI with native WiX and attaches it to the release.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>