We need some way to check when accessToken has expired

[ryderwishart]

Right now we are storing the access token in sessionStorage, and hiding the 'remember me' checkbox (cf. #52).

Ideally, 'remember me' would store the token to localStorage. However, we need some way of determining when the user's token has expired.

Logout has to clear session and local storage once we make a more robust solution.

[woodwardmw]

I now have a workaround for this, in branch #85 - the chatbot_auth_check_decorator adds logged_in: False to the json it returns, if the token isn't verified server-side, and the UI then uses this to prompt the user to log in. This was the only way I could think of doing it without verifying the token client-side, which would involve having the Supabase secrets available client-side.