🎨 fix(theme): align UI controls with global radius tokens

Remove hard-coded and capped border radius overrides so shared controls and feature actions consistently follow the active theme radius.

- Replace fixed radius utilities with semantic theme-aware radius tokens
- Remove redundant `rounded-full` and pixel-based overrides from header, toolbar, Playground, and utility actions
- Drop unused `StatusBadge` rounded prop usage
- Keep existing component behavior intact while improving global theme consistency

web/default/src/components/ai-elements/tool.tsx

@@ -65,7 +65,7 @@ const getStatusBadge = (status: ExtendedToolState) => {
   }
 
   return (
-    <Badge className='gap-1.5 rounded-full text-xs' variant='secondary'>
+    <Badge className='gap-1.5 text-xs' variant='secondary'>
       {icons[status]}
       {labels[status]}
     </Badge>