- Move the decoration image into [candidate_window.decoration] (102x88, right-aligned)
- Add [candidate_window.background] with a translucent texture and 12dip corner radius
- Replace toolbar.css with [toolbar] / [toolbar.dark] / [toolbar.light]
- Bump version to 0.2.0
- Update tests, preview.html and schema docs for the new fields
- Rewrite README