feat: add d4r inference engines and Windows parity tooling

Add native K/M/RR inference engines, HIP kernels, replay and validation
harnesses, and Windows DLSS setup and runtime support. Include GPU
profiling tools, build and packaging scripts, platform integration
patches, and implementation documentation.

scripts/windows/test-gpu-target-contract.ps1

@@ -0,0 +1,23 @@
+[CmdletBinding()]
+param([Parameter(Mandatory=$true)][string]$PackageRoot, [Parameter(Mandatory=$true)][string]$CodeObject)
+$ErrorActionPreference='Stop'
+. (Join-Path $PSScriptRoot 'gpu-target.ps1')
+$target=Get-D4RGpuTarget $PackageRoot $null
+$other=if ($target -eq 'gfx1201') { 'gfx1200' } else { 'gfx1201' }
+function Expect-Rejection([scriptblock]$Action) {
+    $rejected=$false
+    try { & $Action | Out-Null } catch { $rejected=$true }
+    if (!$rejected) { throw 'GPU target contract accepted incompatible input.' }
+}
+if ((Get-D4RGpuTarget $PackageRoot $target) -ne $target) { throw 'Incorrect package target.' }
+Assert-D4RCodeObjectTarget $CodeObject $target
+Expect-Rejection { Get-D4RGpuTarget $PackageRoot $other }
+Expect-Rejection { Get-D4RGpuTarget $PackageRoot 'gfx1250' }
+Expect-Rejection { Assert-D4RCodeObjectTarget $CodeObject $other }
+Expect-Rejection { Assert-D4RCodeObjectTarget (Join-Path $PackageRoot 'gpu-target.json') $target }
+# Old packages had no target metadata and were gfx1201 only.
+$legacy=Join-Path $PackageRoot '__no-target-metadata__'
+if (Test-Path -LiteralPath (Join-Path $legacy 'gpu-target.json')) { throw 'Unexpected legacy test fixture.' }
+if ((Get-D4RGpuTarget $legacy $null) -ne 'gfx1201') { throw 'Legacy target changed.' }
+Expect-Rejection { Get-D4RGpuTarget $legacy 'gfx1200' }
+Write-Host "PASS GPU_TARGET_SCRIPT target=$target rejected=5 hardware_executed=0"