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/d3d12_boundary_timing.h

@@ -0,0 +1,55 @@
+#pragma once
+#include "d3d12_external.h"
+#include <cstring>
+
+namespace d4r::win {
+// Diagnostic timestamps, read only after the copy slot's existing completion
+// fence. No extra queue/CPU wait, and no image readback. The interval across
+// the external fence includes HIP execution and scheduling, not just kernels.
+class BoundaryTiming {
+    ComPtr<ID3D12QueryHeap> queries_;
+    ComPtr<ID3D12Resource> readback_;
+    uint64_t ticket_ = 0;
+public:
+    explicit BoundaryTiming(ID3D12Device* device) {
+        D3D12_QUERY_HEAP_DESC query{};
+        query.Type = D3D12_QUERY_HEAP_TYPE_TIMESTAMP; query.Count = 4;
+        dx(device->CreateQueryHeap(&query, IID_PPV_ARGS(queries_.GetAddressOf())), "Boundary timestamp heap");
+        D3D12_HEAP_PROPERTIES heap{}; heap.Type = D3D12_HEAP_TYPE_READBACK;
+        D3D12_RESOURCE_DESC desc{};
+        desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER; desc.Width = 4 * sizeof(uint64_t);
+        desc.Height = 1; desc.DepthOrArraySize = 1; desc.MipLevels = 1;
+        desc.SampleDesc.Count = 1; desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
+        dx(device->CreateCommittedResource(&heap, D3D12_HEAP_FLAG_NONE, &desc,
+            D3D12_RESOURCE_STATE_COPY_DEST, nullptr, IID_PPV_ARGS(readback_.GetAddressOf())), "Boundary timestamp readback");
+    }
+    void input_begin(ID3D12GraphicsCommandList* list) { list->EndQuery(queries_.Get(), D3D12_QUERY_TYPE_TIMESTAMP, 0); }
+    void input_end(ID3D12GraphicsCommandList* list) { list->EndQuery(queries_.Get(), D3D12_QUERY_TYPE_TIMESTAMP, 1); }
+    void output_begin(ID3D12GraphicsCommandList* list) { list->EndQuery(queries_.Get(), D3D12_QUERY_TYPE_TIMESTAMP, 2); }
+    void output_end(ID3D12GraphicsCommandList* list) {
+        list->EndQuery(queries_.Get(), D3D12_QUERY_TYPE_TIMESTAMP, 3);
+        list->ResolveQueryData(queries_.Get(), D3D12_QUERY_TYPE_TIMESTAMP, 0, 4, readback_.Get(), 0);
+    }
+    void submitted(uint64_t ticket) { ticket_ = ticket; }
+    // Caller has observed the slot's completion fence, including ResolveQueryData.
+    void report(ID3D12CommandQueue* queue, const void* feature) {
+        if (!ticket_) return;
+        uint64_t ticks[4]{}, frequency = 0;
+        D3D12_RANGE read{0, sizeof(ticks)}, written{0, 0};
+        void* mapped = nullptr;
+        dx(readback_->Map(0, &read, &mapped), "Map completed boundary timestamps");
+        std::memcpy(ticks, mapped, sizeof(ticks)); readback_->Unmap(0, &written);
+        dx(queue->GetTimestampFrequency(&frequency), "Boundary timestamp frequency");
+        if (!frequency || !ticks[0] || ticks[0] > ticks[1] || ticks[1] > ticks[2] || ticks[2] > ticks[3])
+            throw std::runtime_error("Invalid completed boundary timestamps");
+        const double ms = 1000. / double(frequency);
+        std::printf("D4R_GPU_BOUNDARY feature=%p ticket=%llu input_copy_ms=%.6f external_span_ms=%.6f output_copy_ms=%.6f total_ms=%.6f input_start_ticks=%llu input_end_ticks=%llu output_start_ticks=%llu output_end_ticks=%llu frequency=%llu diagnostics_cpu_bytes=32 serializing=0\n",
+            feature, (unsigned long long)ticket_, double(ticks[1] - ticks[0]) * ms,
+            double(ticks[2] - ticks[1]) * ms, double(ticks[3] - ticks[2]) * ms,
+            double(ticks[3] - ticks[0]) * ms, (unsigned long long)ticks[0],
+            (unsigned long long)ticks[1], (unsigned long long)ticks[2],
+            (unsigned long long)ticks[3], (unsigned long long)frequency);
+        ticket_ = 0;
+    }
+};
+}