Give nukies the ability to declare war for a TC boost (#19291)

Co-authored-by: Kevin Zheng <kevinz5000@gmail.com>

Content.Server/GameTicking/Rules/Components/GameRuleComponent.cs

@@ -1,4 +1,6 @@
-namespace Content.Server.GameTicking.Rules.Components;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom;
+
+namespace Content.Server.GameTicking.Rules.Components;
 
 /// <summary>
 /// Component attached to all gamerule entities.
@@ -14,6 +16,12 @@ public sealed partial class GameRuleComponent : Component
     [DataField("active")]
     public bool Active;
 
+    /// <summary>
+    /// Game time when game rule was activated
+    /// </summary>
+    [DataField("activatedAt", customTypeSerializer:typeof(TimeOffsetSerializer))]
+    public TimeSpan ActivatedAt;
+
     /// <summary>
     /// Whether or not the gamerule finished.
     /// Used for tracking whether a non-active gamerule has been started before.