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.Server/Data/Entities/CouponEntities.cs

@@ -0,0 +1,47 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace DorkNet.Server.Data.Entities;
+
+/// <summary>
+/// Admin-issued promo coupon. Players redeem by code via
+/// <c>POST /api/coupons/v1/redeem/{code}</c>. Each redemption
+/// inserts a <see cref="CouponRedemptionEntity"/> row (one per
+/// (coupon, player) pair so we can enforce one-redeem-per-player).
+/// </summary>
+public class CouponEntity
+{
+    public long Id { get; set; }
+
+    [MaxLength(64)]
+    public string Code { get; set; } = string.Empty;
+
+    [MaxLength(256)]
+    public string Description { get; set; } = string.Empty;
+
+    /// <summary>RewardType: 0=Currency, 1=ItemSlug, 2=Subscription.</summary>
+    public int RewardType { get; set; }
+
+    /// <summary>Currency type if RewardType=0; otherwise unused.</summary>
+    public int RewardCurrencyType { get; set; }
+
+    public long RewardAmount { get; set; }
+
+    /// <summary>Item slug if RewardType=1.</summary>
+    [MaxLength(64)]
+    public string RewardItemSlug { get; set; } = string.Empty;
+
+    public bool IsActive { get; set; } = true;
+    public int MaxRedemptions { get; set; } = 0;
+    public int RedemptionCount { get; set; } = 0;
+
+    public DateTime? ExpiresAt { get; set; }
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+}
+
+public class CouponRedemptionEntity
+{
+    public long Id { get; set; }
+    public long CouponId { get; set; }
+    public long PlayerId { get; set; }
+    public DateTime RedeemedAt { get; set; } = DateTime.UtcNow;
+}