Cover the callers of the variant generators that had no tests with the
new validation: restoring a deleted variant into its container, restoring
it after its container was deleted, and adding a property and then
setting its value, as the workspace properties panel does. Each case
runs with valid data and expects no validation error on JS.
AI-assisted-by: claude-opus-5-5
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>