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.

tools/windows/gpu-target.json.in

@@ -0,0 +1,6 @@
+{
+  "schema": 1,
+  "architecture": "@D4R_GPU_ARCH@",
+  "wavefrontSize": 32,
+  "validation": "Compilation is not hardware validation; run the GPU diagnostics."
+}