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/Controllers/API/Version/VersionController.cs

@@ -0,0 +1,22 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace DorkNet.Server.Controllers.API.Version;
+
+[ApiController]
+public class VersionController : ControllerBase
+{
+    // VersionStatus enum: ValidForPlay=0, ValidForMenu=1, UpdateRequired=2
+    private static readonly object ValidForPlay = new { VersionStatus = 0 };
+
+    [HttpGet("api/version/v1")]
+    [HttpGet("api/version")]
+    public ActionResult<object> GetV1() => Ok(ValidForPlay);
+
+    // Actual path the 2020 build uses
+    [HttpGet("api/versioncheck/v4")]
+    [HttpGet("api/versioncheck/v3")]
+    [HttpGet("api/versioncheck/v2")]
+    [HttpGet("api/versioncheck/v1")]
+    [HttpGet("api/versioncheck")]
+    public ActionResult<object> GetCheck() => Ok(ValidForPlay);
+}