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.ClientPatch/NuGet.Config

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  BepInEx 6.x bleeding-edge packages live on the BepInEx NuGet
+  feed, not nuget.org. Restore is scoped to this folder only so
+  the project's package references resolve cleanly without polluting
+  the global feed list.
+-->
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="nuget.org"      value="https://api.nuget.org/v3/index.json" />
+    <add key="BepInEx-NuGet"  value="https://nuget.bepinex.dev/v3/index.json" />
+  </packageSources>
+</configuration>