Record login time (and perhaps IP address and other info). This probably needs to be keyed on login identifier, not Org Identity or CO Person. This would also enable a "Last login at X from Y" message to be displayed at login.

While this could be interleaved with History records, that would probably just get noisy.

Access via CO Person/Org Identity sidebars? Or via Identifiers view? Or all of the above? For CO/CMP Admins only?