Initial commit: OpenRA game engine

Fork from OpenRA/OpenRA with one-click launch script (start-ra.cmd)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

utility.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+set -o errexit || exit $?
+
+ENGINEDIR=$(dirname "$0")
+
+ENGINE_DIR=.. dotnet "${ENGINEDIR}/bin/OpenRA.Utility.dll" "$@"