Broadcast alerts

[Siderite]

A feature to alert you when something happened on a board in the same broadcast you are watching, but not the currently selected board.

Things that could happen:

• someone moved (ply/position change)
• evaluation changed substantially (mistake or blunder)
• game ended
• sacrifices or other interesting meta moves

[Siderite]

You should somehow store when you last looked and check from then.