Import december-2020-12-18 from private repo (scrubbed 2026-05-27)

Targets Rec Room 2020.12.18 client.

Re-import after adding:
- DorkNet.ClientMod/dorknet-clientmod.json.template — config schema
  the launcher's manifest-driven patcher renders into UserData/.
- tools/build-patcher-zip.ps1 — produces the dorknet-clientpatch-{key}.zip
  Release asset the launcher fetches.
- .github/workflows/release.yml — auto-publishes both Release assets
  on v1-december-* tag push.

Scrubbed via maintainer-side scrub-for-public.ps1: same drop rules as
the prior import, plus build-patcher-zip.ps1 added to the tools/
allow-list so it survives the scrub.

DorkNet.Models/Avatar/AvatarData.cs

@@ -0,0 +1,24 @@
+using System.Text.Json.Serialization;
+
+namespace DorkNet.Models.Avatar;
+
+public class AvatarData
+{
+    [JsonPropertyName("AccountId")]
+    public long AccountId { get; set; }
+
+    [JsonPropertyName("AvatarItemInstances")]
+    public List<AvatarItemInstance> AvatarItemInstances { get; set; } = [];
+}
+
+public class AvatarItemInstance
+{
+    [JsonPropertyName("Id")]
+    public long Id { get; set; }
+
+    [JsonPropertyName("ItemId")]
+    public long ItemId { get; set; }
+
+    [JsonPropertyName("IsEquipped")]
+    public bool IsEquipped { get; set; }
+}