## Summary
- Adds mobile-friendly drawer UI for the chat sidebar and model family
sidebar
- Introduces responsive header navigation with mobile-specific toggle
buttons
- Uses slide-in drawer overlay pattern on small screens instead of
collapsible sidebars
- Stores mobile drawer state in app store for consistent state
management
## Testing
Tested on desktop (responsive mode) and mobile viewport widths. Sidebars
now slide in as drawers on small screens with proper z-index layering
and close-on-outside-click behavior.
ArvidSU
a6aa07ed83
