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/Geo/GeoController.cs

@@ -0,0 +1,30 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace DorkNet.Server.Controllers.Geo;
+
+/// <summary>
+/// geo.{apex}/v1/regions — region/server geography. Returns a single
+/// configured region (we don't actually run multi-region; the watch's
+/// region picker just needs one entry to populate the dropdown).
+///
+/// The <c>/v1/ping</c> endpoint that previously lived here was
+/// removed during the [Host]-strip refactor — both geo and ns
+/// answered the same path (NsController.Ping is the canonical
+/// one), and with host filters gone the two routes would have
+/// ambiguous-matched on any subdomain. NsController wins because
+/// its ping body carries the timestamp the keep-alive loop reads;
+/// the geo version returned a bare {Ok:true} that nothing consumed.
+/// </summary>
+[ApiController]
+public class GeoController(IConfiguration config) : ControllerBase
+{
+    [HttpGet("/v1/regions")]
+    public ActionResult<List<object>> GetRegions()
+    {
+        var region = config["Photon:CloudRegion"] ?? "us";
+        return Ok(new[]
+        {
+            new { Id = region, Name = region.ToUpperInvariant(), Ping = 50 },
+        });
+    }
+}