fix: remove desktop translucency to reduce macOS compositing cost

packages/ui/src/components/onboarding/OnboardingScreen.tsx

@@ -207,7 +207,7 @@ export function OnboardingScreen({ onCliAvailable }: OnboardingScreenProps) {
 
   return (
     <div
-      className="h-full flex items-center justify-center bg-transparent p-8 relative cursor-default select-none"
+      className="h-full flex items-center justify-center bg-background p-8 relative cursor-default select-none"
       onMouseDown={handleDragStart}
     >
       <div className="w-full space-y-4 text-center">
@@ -241,7 +241,7 @@ export function OnboardingScreen({ onCliAvailable }: OnboardingScreenProps) {
         )}
 
         <div className="flex justify-center">
-          <div className="bg-background/60 backdrop-blur-sm border border-border rounded-lg px-5 py-3 font-mono text-sm w-fit">
+          <div className="bg-background border border-border rounded-lg px-5 py-3 font-mono text-sm w-fit">
             {copied ? (
               <div className="flex items-center justify-center gap-2" style={{ color: 'var(--status-success)' }}>
                 <RiCheckLine className="h-4 w-4" />