publish: add flex-auto to skeleton

-m viewports had overflow out of parent containers;
this uses flex-auto to ensure the skeleton stays within its flex
container.

pkg/interface/publish/src/js/components/skeleton.js

@@ -31,7 +31,7 @@ export class Skeleton extends Component {
             path={props.path}
             invites={props.invites}
             />
-          <div className={"h-100 w-100 relative white-d " + rightPanelHide} style={{
+          <div className={"h-100 w-100 relative white-d flex-auto " + rightPanelHide} style={{
             flexGrow: 1,
           }}>
             {props.children}