Notify user if the authentication situation has changed

Our SAML setup on the dogfood rack has a very low authorization time (like an hour?), and I often find myself poking at something on the console only to have the next form submission whisk me away to a login page.

There's also a potential situation where in another tab you log into another account that might not have the same access you did before.

It would be nice if the console were polling something periodically to determine if the currently logged-in user has changed, and notify the user in some way. (I do not like AWS's version of this where it takes over the console and forces you to reload; I would like to be able to re-log in from another tab and come back to this page and continue whatever it was I was doing. Bonus points if I can middle-click a button or link to open the login page in a new tab.)

Start by reviewing the console's current authentication and SAML login flow, then trace what happens when authorization expires or another tab logs into a different account. Define how periodic checks should notify the user without forcing a reload, and how re-login in another tab should let them return to the current page. No specific files or tests are named in the issue.