Import march-2020-03-10 from private repo (scrubbed 2026-05-27)

Targets Rec Room 2020.03.10 client (also serves 2020.03.06).

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 dorknet-clientpatch-{key}.zip
  for v1-march-* Release uploads.
- .github/workflows/release.yml — on tag push publishes both
  dorknet-server-march_2020_03_10-win-x64.zip and
  dorknet-clientpatch-march_2020_03_10.zip as Release assets.

Same scrub rules as december; tools/build-patcher-zip.ps1 added to
the maintainer-side allow-list so it survives.

DorkNet.Server/Data/Entities/StatsEntities.cs

@@ -0,0 +1,55 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace DorkNet.Server.Data.Entities;
+
+/// <summary>
+/// One leaderboard stat row per (player, statChannel). Backs
+/// <c>api/Leaderboard/v1/SetStats</c> + <c>api/Leaderboard/v2/getPlayerRank</c>.
+///
+/// The 2020 watch's <c>RecNet.Leaderboards</c> uses an int channel
+/// id (e.g. 1=PaintballWins, 2=DodgeballHits, etc.) and a single
+/// long value per channel. A player's "rank" is computed as
+/// <c>1 + count(*)</c> of rows in the same channel with a higher
+/// value.
+/// </summary>
+public class LeaderboardStatEntity
+{
+    public long Id { get; set; }
+    public long PlayerId { get; set; }
+
+    /// <summary>RecNet stat channel id (small int per game mode +
+    /// stat type — e.g. paintball-CTF-wins, dodgeball-hits).</summary>
+    public int StatChannel { get; set; }
+
+    /// <summary>Aggregate stat value. Set semantics depend on
+    /// <see cref="SetMode"/>: 0=Always, 1=OnlyIfHigher, 2=OnlyIfLower,
+    /// 3=Increment. Most stat channels are mode 1 (high score).</summary>
+    public long Value { get; set; }
+
+    public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
+}
+
+/// <summary>
+/// Match-result Elo per (player, game mode). Backs
+/// <c>api/PlayerElo/v1/reportPlayerElo</c>. The 2020 watch reports
+/// an Elo delta after each ranked match (Royale, Paintball,
+/// Soccer); we accumulate it per game mode for matchmaking.
+/// </summary>
+public class PlayerEloEntity
+{
+    public long Id { get; set; }
+    public long PlayerId { get; set; }
+
+    /// <summary>RecNet game mode id (small int). We don't enumerate
+    /// these; the wire just sends an int and we pass it through.</summary>
+    public int GameMode { get; set; }
+
+    /// <summary>Current Elo. Default 1000 on first row.</summary>
+    public int Elo { get; set; } = 1000;
+
+    public int Wins { get; set; }
+    public int Losses { get; set; }
+    public int MatchesPlayed { get; set; }
+
+    public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
+}