transform-in-variant (Ctrl+K on a component) runs a chain of events,
each one committing its own changes. It set the variant-id on the main
instance before setting it on the component, so the shape validation
of that step saw them out of sync and rejected the change.
Set the variant-id on the component first, and give the main instance
an empty variant-name, which is what the validator expects while the
variant has no properties yet.
Add a test that runs transform-in-variant through a test store.
AI-assisted-by: claude-opus-5-5
f741571eb0