fix: update PageHeaderRight styling for user session state

- Modified the background styling of the user authentication section in PageHeaderRight to conditionally apply rounded styles based on the presence of a session user.
- Enhanced visual consistency by ensuring the component adapts its appearance according to user authentication status.

Signed-off-by: Innei <tukon479@gmail.com>

apps/web/src/modules/gallery/PageHeader/PageHeaderRight.tsx

@@ -81,7 +81,7 @@ export const PageHeaderRight = () => {
 
       {/* Auth Section - Only show when useCloud is true */}
       {injectConfig.useCloud && (
-        <div className="bg-material-medium/40 flex items-center gap-1 rounded-lg">
+        <div className={`bg-material-medium/40 flex items-center gap-1 ${sessionUser ? 'rounded-full' : 'rounded-lg'}`}>
           {sessionUser ? <UserMenuButton user={sessionUser} /> : <LoginButton />}
         </div>
       )}