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/install_d4r_runtime.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Stages the pieces a Proton game needs under D4R_RUNTIME_DIR
+# (default ~/.local/share/d4r-dlss):
+#   bin/nvcuda.dll      Wine CUDA bridge (ELF builtin, preloaded by path by the shim)
+#   bin/d4r_nvngx.dll   D3D12-to-CUDA NGX core shim (OptiScaler NvngxPath target)
+#   ngx/_nvngx.dll      official NGX core
+#   dlss/nvngx_dlss.dll official DLSS SR feature DLL (also copied into bin/)
+# usage: install_d4r_runtime.sh PATH_TO_NGX_CORE_DLL PATH_TO_NVNGX_DLSS_DLL
+if [[ $# -ne 2 ]]; then
+  printf 'usage: %s PATH_TO_NGX_CORE_DLL PATH_TO_NVNGX_DLSS_DLL\n' "$0" >&2
+  exit 2
+fi
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+RUNTIME="${D4R_RUNTIME_DIR:-$HOME/.local/share/d4r-dlss}"
+"$ROOT/scripts/build_d4r_nvngx_shim.sh"
+"$ROOT/scripts/build_wine_nvcuda_bridge.sh"
+mkdir -p "$RUNTIME/bin" "$RUNTIME/ngx" "$RUNTIME/dlss"
+cp -f "$ROOT/build/wine-nvcuda/x86_64-unix/nvcuda.dll.so" "$RUNTIME/bin/nvcuda.dll"
+cp -f "$ROOT/build/d4r_nvngx.dll" "$RUNTIME/bin/d4r_nvngx.dll"
+copy_unless_same() { [[ "$(realpath "$1")" == "$(realpath -m "$2")" ]] || cp -f "$1" "$2"; }
+copy_unless_same "$1" "$RUNTIME/ngx/_nvngx.dll"
+copy_unless_same "$2" "$RUNTIME/dlss/nvngx_dlss.dll"
+# The NGX core's CUDA init ignores the feature search paths it is given and
+# scans the directory of the module that calls it, i.e. the shim's.
+cp -f "$RUNTIME/dlss/nvngx_dlss.dll" "$RUNTIME/bin/nvngx_dlss.dll"
+sha256sum "$RUNTIME"/ngx/_nvngx.dll "$RUNTIME"/dlss/nvngx_dlss.dll
+printf 'Installed d4r runtime in %s\n' "$RUNTIME"