Change the damage text message message.

shared/src/commonMain/kotlin/com/pixelized/shared/lwa/protocol/websocket/CampaignMessage.kt

@@ -16,7 +16,8 @@ sealed interface CampaignMessage : SocketMessage, CharacterInstanceIdMessage {
         override val characterSheetId: String,
         override val instanceId: Int,
         val characteristic: CampaignJsonV1.CharacterInstanceJsonV1.CharacteristicV1,
-        val value: Int,
+        val oldValue: Int,
+        val newValue: Int,
     ) : CampaignMessage
 
     @Serializable