make UI mobile-first with responsive breakpoints
- container stacks vertically on mobile, 3-col grid on desktop (768px+)
- message controls appear first on mobile (order: -1)
- buttons 2x2 grid with 44px touch targets on mobile
- state summary stacks vertically on mobile
- infrastructure cards single column on mobile (640px+)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>