Agent live card now uses the sentinel pattern to detect when it scrolls
out of view. When stuck, it collapses to a compact header bar with brand
styling and backdrop blur, with a ChevronUp button to scroll back.
When scrolled back into view, the card seamlessly expands to full view.
Also adds semantic colors to Sonner toast icons (success/info/warning/
error/loading) and fixes icon-to-text alignment in toasts globally.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Migrate all shadcn components into apps/web/components/ui/ so the web app
is fully independent from packages/ui for its UI layer. Update to the
latest shadcn base-nova style. Add missing semantic color variables
(success, warning, info, canvas), font-mono mapping, scrollbar styling,
and wrap Select items in SelectGroup for proper padding.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
