multiplayer refactor

Runtime/Engine/Code/Steam/SteamManager.cs

@@ -24,8 +24,10 @@ namespace RebootKit.Engine.Steam {
             }
             
             IsInitialized = true;
-
+            
             await UniTask.Yield(cancellationToken);
+
+            SteamFriends.OnGameRichPresenceJoinRequested += OnJoinRequested;
         }
         
         internal static void Shutdown() {
@@ -36,9 +38,19 @@ namespace RebootKit.Engine.Steam {
             
             s_Logger.Info("Shutting down Steam Manager...");
             
+            SteamFriends.OnGameRichPresenceJoinRequested -= OnJoinRequested;
             SteamClient.Shutdown();
 
             IsInitialized = false;
         }
+        
+        static void OnJoinRequested(Friend friend, string key) {
+            s_Logger.Info($"Join request received from {friend.Name} with key: {key}");
+            
+            if (string.IsNullOrEmpty(key)) {
+                s_Logger.Warning("Join request key is empty. Cannot process join request.");
+                return;
+            }
+        }
     }
 }