fix: out of stock chip z-index, PersonIcon for unauthenticated users

client/src/features/user/user-menu/ui/UserMenu.tsx

@@ -4,6 +4,7 @@ import IconButton from '@mui/material/IconButton'
 import ListItemText from '@mui/material/ListItemText'
 import Menu from '@mui/material/Menu'
 import MenuItem from '@mui/material/MenuItem'
+import PersonIcon from '@mui/icons-material/Person'
 import type { AuthUser } from '@/shared/model/auth'
 import { UserAvatar } from '@/shared/ui/UserAvatar'
 
@@ -50,7 +51,7 @@ export function UserMenu({ user, isAdmin = false, onNavigate, onLogout }: Props)
               size={28}
             />
           ) : (
-            <UserAvatar userId="guest" avatarUrl={null} avatarType={null} avatarStyle={null} size={28} />
+            <PersonIcon sx={{ fontSize: 28 }} />
           )}
         </Badge>
       </IconButton>