- AuthFailedAt is set when a refreshToken is not valid and an
accessToken can't be generated, meaning it will need a manual action
from the user to provide a new refresh token.
- Calendar/messaging jobs should not be executed if authFailedAt is not
null.
- If sync fails we set authFailedAt
- This information is displayed in the frontend in accounts with a `Sync
Failed` pill
- The user can reconnect his account in the dropdown menu
- A new OAuth flow is triggered
- The account is synced
