app detail page open graph (bug 976653)

What? An extra DB query you say?

Well, it's only when someone directly navigates to an app detail page. That means it won't affect our mobile users, and the vast majority of our browser users.
We could have served the view normally (letting fireplace render the error page) with a 404 status code. I agree that's No big deal, but that'd make us better net citizens.