improve performance section

Author: mindapivessa

docs/mini-apps/design-ux/foundations/mobile-first.mdx

@@ -29,9 +29,10 @@ Mini apps are primarily used on mobile, so adopting a mobile-first design is key
 - **Hover states**: Not available on touch devices
 - **Focus management**: Keyboard and screen reader support
 
-### Performance
-- **Limited battery**: Efficient code and animations
-- **Memory constraints**: Optimize images and assets
+### Performance and Loading State
+- App should load quickly (<2s for main views)
+- Minimize spinners
+- Handle errors gracefully
 
 ## Testing Mobile Experience