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/Controllers/API/Auth/PhotonAuthController.cs

@@ -0,0 +1,43 @@
+using Microsoft.AspNetCore.Mvc;
+using DorkNet.Server.Services;
+
+namespace DorkNet.Server.Controllers.API.Auth;
+
+/// <summary>
+/// Photon custom-auth webhook (api.rec.net).
+///
+/// Configure in Photon dashboard:
+///   Authentication → Custom → URL = https://api.rec.net/api/auth/v1/photon
+///   Query params sent by client: token=&lt;our_jwt&gt;
+///
+/// Photon ResultCode: 1 = success, 2 = fail, 3 = param error
+/// </summary>
+[ApiController]
+public class PhotonAuthController(AuthService authService, PlayerService playerService) : ControllerBase
+{
+    [HttpGet("api/auth/v1/photon")]
+    [HttpPost("api/auth/v1/photon")]
+    public async Task<IActionResult> Authenticate([FromQuery] string? token, [FromQuery] string? Token)
+    {
+        var jwt = token ?? Token;
+
+        if (string.IsNullOrWhiteSpace(jwt))
+            return Ok(new { ResultCode = 3, Message = "Missing token parameter" });
+
+        var playerId = authService.ValidateToken(jwt);
+        if (playerId is null)
+            return Ok(new { ResultCode = 2, Message = "Invalid or expired token" });
+
+        var player = await playerService.GetByIdAsync(playerId.Value);
+        if (player is null)
+            return Ok(new { ResultCode = 2, Message = "Player not found" });
+
+        return Ok(new
+        {
+            ResultCode = 1,
+            Message = "ok",
+            UserId = player.Id.ToString(),
+            Nickname = player.DisplayName ?? player.Username,
+        });
+    }
+}