Add .vsconfig and winget install instructions for VS components

Add .vsconfig listing all required Visual Studio workloads and
components (MSVC v143, ARM64, Spectre, ATL, Clang, UWP, WinUI,
Windows SDK 26100, .NET desktop). Update setup-dev-env.ps1 fix
messages to reference the .vsconfig via VS Installer import or
winget --override.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Ben Hillis

.vsconfig

@@ -0,0 +1,21 @@
+{
+  "version": "1.0",
+  "components": [
+    "Microsoft.Component.MSBuild",
+    "Microsoft.VisualStudio.Component.VC.CoreIde",
+    "Microsoft.VisualStudio.Component.VC.Tools.x86.x64",
+    "Microsoft.VisualStudio.Component.VC.Tools.ARM64",
+    "Microsoft.VisualStudio.Component.VC.Tools.x86.x64.Spectre",
+    "Microsoft.VisualStudio.Component.VC.Tools.ARM64.Spectre",
+    "Microsoft.VisualStudio.Component.VC.ATL",
+    "Microsoft.VisualStudio.Component.VC.ATL.ARM64",
+    "Microsoft.VisualStudio.Component.VC.ATL.Spectre",
+    "Microsoft.VisualStudio.Component.VC.ATL.ARM64.Spectre",
+    "Microsoft.VisualStudio.Component.VC.Llvm.Clang",
+    "Microsoft.VisualStudio.Component.Windows11SDK.26100",
+    "Microsoft.VisualStudio.Component.UWP.VC.ARM64",
+    "Microsoft.VisualStudio.Workload.ManagedDesktop",
+    "Microsoft.VisualStudio.Workload.Universal",
+    "Microsoft.VisualStudio.Workload.NativeDesktop"
+  ]
+}

tools/setup-dev-env.ps1

@@ -12,6 +12,9 @@ Set-StrictMode -Version Latest
 $ErrorActionPreference = "Stop"
 
 $script:Errors = 0
+$script:RepoRoot = (Resolve-Path "$PSScriptRoot\..").Path
+$script:VsConfigPath = Join-Path $script:RepoRoot ".vsconfig"
+$script:VsInstallFix = "Import .vsconfig via VS Installer -> More -> Import configuration, or: winget install Microsoft.VisualStudio.2022.Community --override ""--wait --quiet --config $script:VsConfigPath"""
 
 function Check($Name, $Result, $Fix, [switch]$Optional)
 {
@@ -56,7 +59,7 @@ if (Test-Path $vswhere)
 {
     $vsInstall = & $vswhere -latest -property installationPath 2>$null
 }
-Check "Visual Studio 2022+" ($null -ne $vsInstall) "Install Visual Studio 2022: https://visualstudio.microsoft.com/"
+Check "Visual Studio 2022+" ($null -ne $vsInstall) $script:VsInstallFix
 
 # --- VS Components (only check if VS is found) ---
 if ($vsInstall)
@@ -69,24 +72,24 @@ if ($vsInstall)
 
     # Check for specific required components via their markers
     $clangPath = Join-Path $vsInstall "VC\Tools\Llvm\x64\bin\clang-format.exe"
-    Check "C++ Clang Compiler for Windows" (Test-Path $clangPath) "VS Installer -> Modify -> Individual Components -> C++ Clang Compiler for Windows"
+    Check "C++ Clang Compiler for Windows" (Test-Path $clangPath) $script:VsInstallFix
 
     $atlPath = Get-ChildItem -Path (Join-Path $vsInstall "VC\Tools\MSVC") -Filter "atlbase.h" -Recurse -ErrorAction SilentlyContinue | Select-Object -First 1
-    Check "C++ ATL for latest v143 tools" ($null -ne $atlPath) "VS Installer -> Modify -> Individual Components -> C++ ATL for latest v143 build tools"
+    Check "C++ ATL for latest v143 tools" ($null -ne $atlPath) $script:VsInstallFix
 
     $msbuild = Get-Command "msbuild" -ErrorAction SilentlyContinue
     if (-not $msbuild)
     {
         $msbuild = Get-ChildItem -Path $vsInstall -Filter "MSBuild.exe" -Recurse -ErrorAction SilentlyContinue | Select-Object -First 1
     }
-    Check "MSBuild" ($null -ne $msbuild) "VS Installer -> Modify -> Individual Components -> MSBuild"
+    Check "MSBuild" ($null -ne $msbuild) $script:VsInstallFix
 }
 
 # --- Windows SDK ---
 Write-Host ""
 Write-Host "Windows SDK:" -ForegroundColor White
 $sdkPath = "${env:ProgramFiles(x86)}\Windows Kits\10\Include\10.0.26100.0"
-Check "Windows SDK 26100" (Test-Path $sdkPath) "VS Installer -> Modify -> Individual Components -> Windows 11 SDK (10.0.26100.0)"
+Check "Windows SDK 26100" (Test-Path $sdkPath) $script:VsInstallFix
 
 # --- NuGet Credential Provider (Azure DevOps feed) ---
 # nuget.exe resolves credential provider plugins using a priority chain: