Extract shared kiwi→SceneNode conversion into kiwi-convert.ts, used by
both fig-import.ts (.fig file opening) and clipboard.ts (Figma paste).
The clipboard import was a simplified copy that diverged over time:
- Missing SYMBOL→COMPONENT type mapping (Figma's kiwi name for components)
- textAutoResize hardcoded to NONE instead of using clipboard value
- No gradient/image fill support, no effects, no style runs
- Missing flipX/flipY, constraints, text decorations, arc data, etc.
- Percent letter spacing not converted to pixels
Now both paths use nodeChangeToProps() with identical conversion logic.