The patch-building scope ran RefreshPatchBuildingPanel directly on the
refresh worker, where it read the commit-files selection and set the patch
view's origin off the UI thread — the latter raced the UI thread's draw.
Bounce it onto the UI thread, exactly as the staging panel just above
already does, guarded on the generation so a repo switch drops it.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>