added packaging

Packaging/Tools/SdkTools.csproj

@@ -0,0 +1,24 @@
+<!--
+  The project exists for the sake of a single dependency: the package brings
+  makeappx.exe. That way the MSIX build gets by without an installed Windows SDK
+  and repeats itself on any machine that has the .NET SDK. The project is not
+  meant to be built — build-msix.ps1 restores it and takes the program from the
+  packages folder. It is kept out of the build in CursorLang.sln for the same
+  reason.
+-->
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net10.0</TargetFramework>
+        <IsPackable>false</IsPackable>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.Windows.SDK.BuildTools" Version="10.0.26100.6584">
+            <!-- Only the programs from the package are needed, there are no assemblies to reference -->
+            <ExcludeAssets>all</ExcludeAssets>
+            <GeneratePathProperty>true</GeneratePathProperty>
+        </PackageReference>
+    </ItemGroup>
+
+</Project>