Misc replay related changes (#13250)

Content.Shared/Administration/SharedNetworkResourceManager.cs

@@ -1,5 +1,6 @@
 using Robust.Shared.ContentPack;
 using Robust.Shared.Network;
+using Robust.Shared.Serialization;
 using Robust.Shared.Utility;
 
 namespace Content.Shared.Administration;
@@ -38,4 +39,14 @@ public abstract class SharedNetworkResourceManager : IDisposable
         // MemoryContentRoot uses a ReaderWriterLockSlim, which we need to dispose of.
         ContentRoot.Dispose();
     }
+
+    // TODO REPLAYS
+    // Figure out a way to just directly save NetMessage objects to replays. This just uses IRobustSerializer as a crutch.
+
+    [Serializable, NetSerializable]
+    public sealed class ReplayResourceUploadMsg
+    {
+        public byte[] Data = default!;
+        public ResourcePath RelativePath = default!;
+    }
 }