As a User, I want to see unread notifications, so I get timely notifications without a lot of confusing older messages.

This is "read" functionality for the timestamps. The timestamps are read on the server side by the Echo notification code, and change the appearance of the "notifications" and "alerts" indicators on each wiki page. There are potential race conditions if the timestamp was recently written in another data centre and the row has not yet propagated.

Priority: must have