chore(ui): redesign interface with SF Pro fonts and modern styling

- Update theme variables and styles for light/dark modes
- Implement SF Pro font family across all components
- Redesign cards, buttons, forms, and scrollbars
- Add backdrop filters and improve visual hierarchy
- Optimize spacing, typography, and interactive elements

.gitignore

@@ -22,8 +22,9 @@ docs/_book
 
 # TODO: where does this rule come from?
 test/
+dist/
 
 node_modules/
-
+design.md
 agent.md
 api-backend.md