feat: modify default avatar (#2034)

apps/web/src/components/affine/workspace-setting-detail/panel/general/style.ts

@@ -42,6 +42,7 @@ export const StyledAvatar = styled('div')(
         backgroundColor: 'rgba(60, 61, 63, 0.5)',
         justifyContent: 'center',
         alignItems: 'center',
+        zIndex: 10,
       },
     };
   }