🎨 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/features/channels/components/dialogs/codex-usage-dialog.tsx

@@ -264,7 +264,7 @@ function RateLimitGroupSection(props: RateLimitGroupSectionProps) {
           <div className='text-muted-foreground flex flex-wrap items-center gap-2 text-xs'>
             {props.description && <span>{props.description}</span>}
             {props.meteredFeature && (
-              <span className='bg-muted/60 inline-flex max-w-full items-center gap-2 rounded-full px-2 py-0.5'>
+              <span className='bg-muted/60 inline-flex max-w-full items-center gap-2 rounded-md px-2 py-0.5'>
                 <span className='text-[11px]'>metered_feature</span>
                 <span className='min-w-0 font-mono text-xs break-all'>
                   {props.meteredFeature}