Send and read messages

Messages are private, between two players.

1. Message on a player's card writes to them. Messages keeps your conversations.
2. Send Message delivers it at once if they are online, else when they next come.

3. The other player sees the number of unread messages on Messages.
4. On a phone: the other player sees the number of unread messages on Messages, in the bar at the bottom.
5. Messages lists their conversations, the latest first.

6. The answer appears in your conversation as it arrives.