1v1 me first to 31 no powerups [Deathmatch Gamemode] (#19467)

Co-authored-by: Kara <lunarautomaton6@gmail.com>

Content.Server/KillTracking/KillTrackerComponent.cs

@@ -0,0 +1,62 @@
+using Content.Shared.FixedPoint;
+using Content.Shared.Mobs;
+using Robust.Shared.Network;
+
+namespace Content.Server.KillTracking;
+
+/// <summary>
+/// This is used for entities that track player damage sources and killers.
+/// </summary>
+[RegisterComponent, Access(typeof(KillTrackingSystem))]
+public sealed partial class KillTrackerComponent : Component
+{
+    /// <summary>
+    /// The mobstate that registers as a "kill"
+    /// </summary>
+    [DataField("killState")]
+    public MobState KillState = MobState.Critical;
+
+    /// <summary>
+    /// A dictionary of sources and how much damage they've done to this entity over time.
+    /// </summary>
+    [DataField("lifetimeDamage")]
+    public Dictionary<KillSource, FixedPoint2> LifetimeDamage = new();
+}
+
+public abstract record KillSource;
+
+/// <summary>
+/// A kill source for players
+/// </summary>
+[DataDefinition, Serializable]
+public sealed partial record KillPlayerSource : KillSource
+{
+    [DataField("playerId")]
+    public NetUserId PlayerId;
+
+    public KillPlayerSource(NetUserId playerId)
+    {
+        PlayerId = playerId;
+    }
+}
+
+/// <summary>
+/// A kill source for non-player controlled entities
+/// </summary>
+[DataDefinition, Serializable]
+public sealed partial record KillNpcSource : KillSource
+{
+    [DataField("npcEnt")]
+    public EntityUid NpcEnt;
+
+    public KillNpcSource(EntityUid npcEnt)
+    {
+        NpcEnt = npcEnt;
+    }
+}
+
+/// <summary>
+/// A kill source for kills with no damage origin
+/// </summary>
+[DataDefinition, Serializable]
+public sealed partial record KillEnvironmentSource : KillSource;