i'm looking to setup a XF install which respects my existing application's authentication. my goal is to have the user never, ever login to XF directly but instead login to my application and have XF use the session cookie i create to figure out who they are. are there any examples of this behavior i can use as a base? what files should i look to edit in XF in order to bypass the built-in auth and read my custom cookie for session info? thanks!