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/prepare-zluda-llvm-source.ps1

@@ -0,0 +1,34 @@
+[CmdletBinding()]
+param([Parameter(Mandatory=$true)][string]$LlvmSourceRoot)
+$ErrorActionPreference='Stop'
+$repo=[IO.Path]::GetFullPath((Join-Path $PSScriptRoot '../..'))
+$expected='ff4dc1f7c9e1c64d4d69e40f4ed30c2280a96dfd'
+$actual=(& git -C $LlvmSourceRoot rev-parse HEAD).Trim()
+if ($LASTEXITCODE -or $actual -ne $expected) { throw "Expected audited ZLUDA LLVM source $expected, found $actual; review the patch against this revision." }
+$patches=@(Get-ChildItem (Join-Path $repo 'patches/zluda-llvm') -Filter *.patch | Sort-Object Name)
+foreach ($patch in $patches) {
+    $oldPreference=$ErrorActionPreference
+    try {
+        $ErrorActionPreference='Continue'
+        & git -C $LlvmSourceRoot apply --reverse --check $patch.FullName 2>$null
+        $applied=($LASTEXITCODE -eq 0)
+    } finally { $ErrorActionPreference=$oldPreference }
+    if (!$applied) {
+        & git -C $LlvmSourceRoot apply --check $patch.FullName
+        if ($LASTEXITCODE) { throw "LLVM source patch conflicts: $($patch.Name)" }
+        & git -C $LlvmSourceRoot apply $patch.FullName
+        if ($LASTEXITCODE) { throw "LLVM source patch failed: $($patch.Name)" }
+    }
+    Write-Host "LLVM source patch present: $($patch.Name)"
+}
+# The pinned backport is the entire intended LLVM delta.
+if ($patches.Count -ne 1) { throw 'Review combined LLVM source provenance before adding more patches.' }
+$audit=Join-Path $repo ('build/llvm-source-audit-'+[Guid]::NewGuid().ToString('N')+'.patch')
+New-Item -ItemType Directory -Force (Split-Path $audit) | Out-Null
+try {
+    & git -C $LlvmSourceRoot diff --binary --output=$audit
+    if ($LASTEXITCODE) { throw 'Cannot audit LLVM source diff.' }
+    $actualDiff=[IO.File]::ReadAllText($audit).Replace("`r`n","`n").TrimEnd()
+    $expectedDiff=[IO.File]::ReadAllText($patches[0].FullName).Replace("`r`n","`n").TrimEnd()
+    if ($actualDiff -cne $expectedDiff) { throw 'LLVM source contains changes outside the exported audited patch.' }
+} finally { if (Test-Path -LiteralPath $audit) { Remove-Item -LiteralPath $audit } }