Should handle the cases of people leaving their app open for long durations (>24h) more robustly. Currently, we don't continuously refresh our access token (which expires after 24h) after the initial app login, so things may break if you try to use the app after it expires.

This handles a few more cases by adding a

• periodic access token refresh timer with an interval of 3 hours, and
• an additional access token refresh event when the window is focused and the current token is at least an hour old

This should additionally handle the case where the device goes to sleep for >24hours and wakes up again (though the user would need to click on the window to focus it and refresh the token). Having that done automatically might be useful but can be done in a separate PR if we need it.