Fix drone hat offset (#6978)

Content.Shared/Clothing/ClothingEvents.cs

@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-using Robust.Shared.GameObjects;
 using static Robust.Shared.GameObjects.SharedSpriteComponent;
 
 namespace Content.Shared.Clothing;
@@ -7,7 +5,7 @@ namespace Content.Shared.Clothing;
 /// <summary>
 ///     Raised directed at a piece of clothing to get the set of layers to show on the wearer's sprite
 /// </summary>
-public class GetEquipmentVisualsEvent : EntityEventArgs
+public sealed class GetEquipmentVisualsEvent : EntityEventArgs
 {
     /// <summary>
     ///     Entity that is wearing the item.
@@ -37,7 +35,7 @@ public class GetEquipmentVisualsEvent : EntityEventArgs
 /// <remarks>
 ///     Useful for systems/components that modify the visual layers that an item adds to a player. (e.g. RGB memes)
 /// </remarks>
-public class EquipmentVisualsUpdatedEvent : EntityEventArgs
+public sealed class EquipmentVisualsUpdatedEvent : EntityEventArgs
 {
     /// <summary>
     ///     Entity that is wearing the item.

Content.Shared/Inventory/InventoryTemplatePrototype.cs

@@ -34,6 +34,11 @@ public sealed class SlotDefinition
     [DataField("dependsOn")] public string? DependsOn { get; }
 
     [DataField("displayName", required: true)] public string DisplayName { get; } = string.Empty;
+
+    /// <summary>
+    ///     Offset for the clothing sprites.
+    /// </summary>
+    [DataField("offset")] public Vector2 Offset { get; } = Vector2.Zero;
 }
 
 public enum SlotUIContainer