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/send-game-key.ps1

@@ -0,0 +1,32 @@
+[CmdletBinding()]
+param([Parameter(Mandatory=$true)][int]$GameProcessId,
+    [ValidateSet('Enter','Escape','Up','Down','Tab','Space')][string]$Key='Enter')
+$ErrorActionPreference='Stop'
+$process=Get-Process -Id $GameProcessId -ErrorAction Stop
+if ($process.ProcessName -eq 'GhostOfTsushima') {
+    $expected='C:\Program Files (x86)\Steam\steamapps\common\Ghost of Tsushima DIRECTOR''S CUT\GhostOfTsushima.exe'
+    if ($process.Path -ine $expected) { throw 'Ghost of Tsushima process path does not match the authorized Steam installation.' }
+} elseif ($process.ProcessName -ne 'SHProto-Win64-Shipping') {
+    throw 'This helper only accepts the authorized Ghost of Tsushima or Silent Hill 2 diagnostic process.'
+}
+if (!('D4RGameKeys' -as [type])) {
+    Add-Type @'
+using System;
+using System.Runtime.InteropServices;
+public static class D4RGameKeys {
+    [DllImport("user32.dll")] public static extern bool PostMessage(IntPtr window, uint message, IntPtr key, IntPtr flags);
+    [DllImport("user32.dll")] public static extern uint MapVirtualKey(uint code, uint kind);
+    [DllImport("user32.dll")] public static extern IntPtr GetForegroundWindow();
+}
+'@
+}
+$window=$process.MainWindowHandle
+if ($window -eq [IntPtr]::Zero) { throw 'Game window missing on this desktop.' }
+if ([D4RGameKeys]::GetForegroundWindow() -ne $window) { throw 'Target game is not foreground; key was not sent.' }
+$codes=@{Enter=13; Escape=27; Up=38; Down=40; Tab=9; Space=32}
+$code=$codes[$Key]; $scan=[D4RGameKeys]::MapVirtualKey($code,0)
+$flags=[long](1 -bor ($scan -shl 16))
+if ($Key -in @('Up','Down')) { $flags=$flags -bor 0x01000000 }
+if (![D4RGameKeys]::PostMessage($window,0x100,[IntPtr]$code,[IntPtr]$flags)) { throw 'Game key-down post failed.' }
+if (![D4RGameKeys]::PostMessage($window,0x101,[IntPtr]$code,[IntPtr]($flags -bor 0xc0000000L))) { throw 'Game key-up post failed.' }
+Write-Host "Sent $Key only to diagnostic game PID $GameProcessId."