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>

OpenRA.Mods.Common/Installer/SourceResolvers/GogSourceResolver.cs

@@ -0,0 +1,53 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Runtime.InteropServices;
+using Microsoft.Win32;
+
+namespace OpenRA.Mods.Common.Installer
+{
+	public class GogSourceResolver : ISourceResolver
+	{
+		public string FindSourcePath(ModContent.ModSource modSource)
+		{
+			var appId = modSource.Type.NodeWithKeyOrDefault("AppId");
+
+			if (appId == null)
+				return null;
+
+			if (Platform.CurrentPlatform != PlatformType.Windows)
+				return null;
+
+			// We need an extra check for the platform here to silence a warning when the registry is accessed
+			// TODO: Remove this once our platform checks use the same method
+			if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+				return null;
+
+			var prefixes = new[] { "HKEY_LOCAL_MACHINE\\Software\\", "HKEY_LOCAL_MACHINE\\SOFTWARE\\Wow6432Node\\" };
+
+			foreach (var prefix in prefixes)
+			{
+				if (Registry.GetValue($"{prefix}GOG.com\\Games\\{appId.Value.Value}", "path", null) is not string installDir)
+					continue;
+
+				if (InstallerUtils.IsValidSourcePath(installDir, modSource))
+					return installDir;
+			}
+
+			return null;
+		}
+
+		public Availability GetAvailability()
+		{
+			return Platform.CurrentPlatform != PlatformType.Windows ? Availability.DigitalInstall : Availability.Unavailable;
+		}
+	}
+}