started working on player moves.

Shogi.Domain/Aggregates/Session.cs

@@ -23,4 +23,9 @@ public class Session
 		if (Player2 != null) throw new InvalidOperationException("Player 2 already exists while trying to add a second player.");
 		Player2 = player2Name;
 	}
+
+	public bool IsSeated(string playerName)
+	{
+		return Player1 == playerName || Player2 == playerName;
+	}
 }