Add server synchronization feature.

shared/src/commonMain/kotlin/com/pixelized/shared/lwa/model/characterSheet/factory/CharacterSheetJsonFactory.kt

@@ -10,7 +10,7 @@ import com.pixelized.shared.lwa.protocol.rest.CharacterPreviewJson
 class CharacterSheetJsonFactory(
     private val v1: CharacterSheetJsonV1Factory,
 ) {
-    suspend fun convertFromJson(
+    fun convertFromJson(
         json: CharacterSheetJson,
     ): CharacterSheet {
         return when (json) {

shared/src/commonMain/kotlin/com/pixelized/shared/lwa/model/characterSheet/factory/CharacterSheetJsonV1Factory.kt

@@ -7,7 +7,7 @@ import com.pixelized.shared.lwa.usecase.CharacterSheetUseCase
 class CharacterSheetJsonV1Factory(
     private val characterSheetUseCase: CharacterSheetUseCase,
 ) {
-    suspend fun convertFromJson(
+    fun convertFromJson(
         json: CharacterSheetJsonV1,
     ): CharacterSheet = characterSheetUseCase.run {
         CharacterSheet(

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

@@ -0,0 +1,10 @@
+package com.pixelized.shared.lwa.protocol.websocket
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+sealed interface GameAdminEvent : SocketMessage {
+
+    @Serializable
+    data class ServerSynchronization(override val timestamp: Long) : GameAdminEvent
+}