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/d4r_ngx_param_host.cpp

@@ -0,0 +1,18 @@
+// MinGW-side support for d4r_ngx_param_msvc.cpp: allocation hooks for the
+// parameter objects and the MSVC floating-point marker symbol that clang-cl
+// objects reference.
+#include <cstdlib>
+
+extern "C" {
+int _fltused = 0;
+}
+
+extern "C" void* d4r_host_alloc(unsigned long long size)
+{
+    return std::calloc(1, static_cast<size_t>(size));
+}
+
+extern "C" void d4r_host_free(void* pointer)
+{
+    std::free(pointer);
+}