You can and should not use navigation rules for non-JSF resources. JSF assumes that all to-view-ids are real JSF views in the current webapp (otherwise, they wouldn't be called "view IDs" in first place).
Just use ExternalContext#redirect()
.
public void redirect() throws IOException {
// ...
FacesContext.getCurrentInstance().getExternalContext().redirect("/staticWebRoot/logout.xhtml");
}