Add patch for replay gem counter

Patches/GemReplayPatch.cs

@@ -0,0 +1,26 @@
+using HarmonyLib;
+
+namespace Sandbox.Patches
+{
+	/*
+	 * Fixes the gem counter when watching a replay
+	 */
+	[HarmonyPatch(typeof(GameHUD), "SetGems")]
+	internal class GameHUDSetGemsPatch
+	{
+		static bool Prefix(ref int collected)
+		{
+			// TODO, validate that we're actually writing to SelfGemCounter and not GhostGemCounter
+			// Though I don't think you can watch a replay and ghost at the same time, so it's probably ok
+			if (MarbleManager.Replaying)
+			{
+				MarbleController player = CameraController.instance?.player;
+				if (player)
+				{
+					collected = player.CollectedGems;
+				}
+			}
+			return true;
+		}
+	}
+}