[daisy] Change default redirect for site

[Nick]

I have a site that is only accessible to certain accounts. Currently, if a
person signs out of Daisy while they're viewing a document within this site,
they get redirected to the site's home page.

Since they signed out, however, they see the "access denied ... for user guest"
error page. They also lose the navigation bar, and thus any link back to the
pages they do have access to. In effect, they're stuck unless they manually
enter the URL of a page they do have access to.

Is it possible to override this default behavior, so that instead of returning
to the site's home page, they are redirected to some document that I designate?