Mechanisim to alert when the auth session is ending

[dogmatic69]

By default the time period authentication to a specific institution is valid for is limited (around 90 days). Need a way to notify and re-auth before it ends to ensure continuous data.

Possibly have an attribute like authentication_required which is false to start with but then a few days before the expiry changes to true. Will require tracking / knowing when the auth was done but seems the agreement date is from creation regardless of renewal etc.

Another (less ideal) option would be to detect when it becomes invalid and notify so that it can be done ASAP after becoming invalid.