Automatic holiday sprites (#22929)

Content.Server/Holiday/HolidayVisualsComponent.cs

@@ -0,0 +1,17 @@
+using Robust.Shared.Prototypes;
+
+namespace Content.Server.Holiday;
+
+/// <summary>
+/// This is used for an entity that enables unique visuals on specified holidays.
+/// </summary>
+[RegisterComponent]
+public sealed partial class HolidayVisualsComponent : Component
+{
+    /// <summary>
+    /// A dictionary relating a generic key to a list of holidays.
+    /// If any of the holidays are being celebrated, that key will be set for holiday visuals.
+    /// </summary>
+    [DataField]
+    public Dictionary<string, List<ProtoId<HolidayPrototype>>> Holidays = new();
+}