Prevent crash during SSO token expiration

[grantfitzsimmons]

Describe the bug
When an SSO authorization token expires due to inactivity, Specify 7 currently loses application state and may crash if the user attempts a refresh. The crash originates from the identity provider (login.ufl.edu), and Specify does not handle or communicate token expiry in a user-friendly way.

To Reproduce

1. Log into Specify 7 using an SSO provider (e.g., login.ufl.edu).
2. Navigate to a record set and open a Batch Edit or run a Query.
3. Leave the app idle until the SSO token expires.
4. Attempt any interaction or click Refresh.
5. See either a crash or unhandled redirect from the identity provider.

Requirements

• Do not attempt background token renewal or preserve user state on expiry.
• Warn users shortly before their session expires with a dialog allowing them to keep their session alive ("Your session will expire in 5 minutes. Click OK to stay logged in.").
  (It would be neat if this hooked into the browser's warning system to bring their attention to the tab).
• On expiry, display a dialog:
  “This session has expired. You have been logged out.”
• After acknowledging the dialog, redirect users to the login screen.

Reported By
Warren, University of Florida