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/run_d3d12_hip_interop_probe.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Zero-copy D3D12 <-> HIP sharing probe under Proton (see the .cpp).
+# usage: run_d3d12_hip_interop_probe.sh PROTON_DIR REPORT_FILE [WIDTH HEIGHT]
+if [[ $# -lt 2 ]]; then
+  printf 'usage: %s PROTON_DIR REPORT_FILE [WIDTH HEIGHT]\n' "$0" >&2
+  exit 2
+fi
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+PROTON_DIR="$(realpath "$1")"
+REPORT="$(realpath -m "$2")"
+shift 2
+source "$ROOT/scripts/d4r_proton_env.sh"
+"$ROOT/scripts/build_d3d12_hip_interop_probe.sh" >/dev/null
+export STEAM_COMPAT_CLIENT_INSTALL_PATH="${STEAM_COMPAT_CLIENT_INSTALL_PATH:-$HOME/.local/share/Steam}"
+export STEAM_COMPAT_DATA_PATH="${D4R_PROTON_COMPAT_DATA:-${TMPDIR:-/tmp}/d4r-proton-harness-compat}"
+mkdir -p "$STEAM_COMPAT_DATA_PATH"
+"$PROTON_DIR/proton" run "$ROOT/build/d3d12_hip_interop_probe.exe" \
+  "$(d4r_winpath "$D4R_RUNTIME_DIR/bin/nvcuda.dll")" "$(d4r_winpath "$REPORT")" "$@" || status=$?
+cat "$REPORT"
+exit "${status:-0}"