make dragons breathe fire (#26746)

* add ActionGun system

* add RepeatingTrigger

* dragons breath projectile, repeatedly explodes

* give dragon fire breathing action, fireproof it

* oop

* oop 2

* prevent troll

* proper repeating thing

* pro

* webedit ops

* realops

---------

Co-authored-by: deltanedas <@deltanedas:kde.org>

Content.Server/Explosion/Components/ExplosiveComponent.cs

@@ -81,6 +81,13 @@ public sealed partial class ExplosiveComponent : Component
     [DataField("deleteAfterExplosion")]
     public bool? DeleteAfterExplosion;
 
+    /// <summary>
+    /// Whether to not set <see cref="Exploded"/> to true, allowing it to explode multiple times.
+    /// This should never be used if it is damageable.
+    /// </summary>
+    [DataField]
+    public bool Repeatable;
+
     /// <summary>
     ///     Avoid somehow double-triggering this explosion (e.g. by damaging this entity from its own explosion.
     /// </summary>

Content.Server/Explosion/Components/RepeatingTriggerComponent.cs

@@ -0,0 +1,25 @@
+using Content.Server.Explosion.EntitySystems;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom;
+
+namespace Content.Server.Explosion.Components;
+
+/// <summary>
+/// Constantly triggers after being added to an entity.
+/// </summary>
+[RegisterComponent, Access(typeof(TriggerSystem))]
+[AutoGenerateComponentPause]
+public sealed partial class RepeatingTriggerComponent : Component
+{
+    /// <summary>
+    /// How long to wait between triggers.
+    /// The first trigger starts this long after the component is added.
+    /// </summary>
+    [DataField]
+    public TimeSpan Delay = TimeSpan.FromSeconds(1);
+
+    /// <summary>
+    /// When the next trigger will be.
+    /// </summary>
+    [DataField(customTypeSerializer: typeof(TimeOffsetSerializer)), AutoPausedField]
+    public TimeSpan NextTrigger;
+}