Add some minor setup behavior to DummyGameTicker by giving it a common base with normal GameTicker.

Necessary for the game to, well, function.

Content.Server/GameTicking/GameTickerBase.cs

@@ -0,0 +1,41 @@
+using Content.Server.Players;
+using Content.Shared;
+using Robust.Server.Interfaces.Player;
+using Robust.Server.Player;
+using Robust.Shared.Enums;
+using Robust.Shared.IoC;
+using Robust.Shared.Timers;
+
+#nullable enable
+
+namespace Content.Server.GameTicking
+{
+    /// <summary>
+    ///     Handles some low-level GameTicker behavior such as setting up clients when they connect.
+    ///     Does not contain lobby/round handling mechanisms.
+    /// </summary>
+    public abstract class GameTickerBase : SharedGameTicker
+    {
+        [Dependency] protected readonly IPlayerManager PlayerManager = default!;
+
+        public virtual void Initialize()
+        {
+            PlayerManager.PlayerStatusChanged += PlayerStatusChanged;
+        }
+
+        protected virtual void PlayerStatusChanged(object sender, SessionStatusEventArgs args)
+        {
+            var session = args.Session;
+
+            if (args.NewStatus == SessionStatus.Connected)
+            {
+                // Always make sure the client has player data. Mind gets assigned on spawn.
+                if (session.Data.ContentDataUncast == null)
+                    session.Data.ContentDataUncast = new PlayerData(session.SessionId);
+
+                // timer time must be > tick length
+                Timer.Spawn(0, args.Session.JoinGame);
+            }
+        }
+    }
+}