During .fig import, instance nodes have no children — Figma expects
them to be cloned from their component. The componentId references
used original Figma GUIDs that didn't match our generated node IDs.
Fix:
- Track original GUID → new node ID mapping during import
- Remap all instance componentId references after node creation
- Iteratively populate empty instances from their components
(multiple passes needed since cloning creates new instances)
Tauri's loadFont registered fonts with the CanvasKit provider but
not in core's loadedFamilies cache, so isFontLoaded returned false
and measureTextNode returned null during layout recomputation.
Add markFontLoaded() to core and call it from Tauri font loader.
Add tests verifying text measurement integrates with auto-layout
centering.
- Fix axis mapping for nested frames with different layout directions
(e.g. vertical child inside horizontal parent had swapped sizing)
- Fix stretch alignment not applying to leaf children when set on parent
- Fix layoutGrow being ignored on children with FIXED primaryAxisSizing
- Add 42 unit tests covering all layout scenarios
