TriggerOnPlayerSpawnComplete and ExplosionOnTrigger (#39820)

Content.Shared/Trigger/Components/Triggers/TriggerOnPlayerSpawnCompleteComponent.cs

@@ -0,0 +1,11 @@
+using Content.Shared.GameTicking;
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Trigger.Components.Triggers;
+
+/// <summary>
+/// A trigger which occurs on <see cref="PlayerSpawnCompleteEvent"/>.
+/// </summary>
+/// <remarks>This does not work with <see cref="TraitSystem"/>, as it would add this component while the event is getting raised.</remarks>
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState]
+public sealed partial class TriggerOnPlayerSpawnCompleteComponent : BaseTriggerOnXComponent;