forked from 1b-agent/opencadstudio-upstream
#1286 added the drag-to-install Applications symlink to packaging/build_macos_signed.sh, but official DMGs come from release.yml, which still ran `hdiutil create -srcfolder OpenCADStudio.app`. That image holds only the app, so the merge had no effect on the downloads #769 is about. Stage the app beside an /Applications symlink, as the signing script does, and build the image from that folder. A new step mounts the result and fails the job unless the app is present, `Applications` points at /Applications, and the app's signature still verifies. Untagged runs upload the DMG as a workflow artifact, as the snap job does, so the layout can be checked without cutting a release. Co-Authored-By: Claude Opus 5.5 <[email protected]>