Fix Windows NVAPI loading the gfx1101 build on every other AMD GPU

0.1.5 shipped one d4r/zluda/nvapi64.dll (the gfx1101 build) for all
targets, and compat_nvapi_path() preferred it over d4r/nvapi/<arch>/.
Nothing on Windows ever set D4R_GPU_ARCH, so on any other GPU NVAPI
failed with "No selected gfx1101 device", NGX CUDA init failed, and
DLSS stayed unavailable (black frames, no OptiScaler upscaler section).

- Select the NVAPI per architecture; never fall back to a shared DLL
  in a multi-target folder, and report a missing build by name.

- The loader and runtime publish D4R_GPU_ARCH and D4R_GPU_LUID for the
  game's adapter, so NVAPI picks the right device with several GPUs.

- nvapi64.dll exports the target it was built for; the runtime refuses
  a mismatch, and the packager and d4r-check read the same marker.

- Release packaging no longer ships d4r/zluda/nvapi64.dll and rejects
  NVAPI builds for the wrong target, without a marker, or missing.

- Move target resolution, device matching and loader choice into
  gpu_selection.h; regression tests cover all 11 targets, bad or
  missing D4R_GPU_ARCH, mixed installs, multi-GPU and missing files.

- d4r-check: accept the FSR keys in the shipped d4r.ini.

scripts/windows/gpu-target.ps1

@@ -36,3 +36,12 @@ function Assert-D4RCodeObjectTarget([string]$Path, [string]$Target) {
     $expected=$info.elfMachine
     if ($header[48] -ne $expected) { throw "Code object does not target ${Target}: $Path (ELF machine=$($header[48]))" }
 }
+# The compatibility NVAPI names the GPU target it was built for (nvapi_trace.cpp); a copy for another GPU, or one
+# built before the marker existed, must never be packaged: it would refuse the GPU it is installed for.
+function Assert-D4RNvapiTarget([string]$Path, [string]$Target) {
+    [void](Get-D4RGpuTargetInfo $Target)
+    $text=[Text.Encoding]::GetEncoding(28591).GetString([IO.File]::ReadAllBytes($Path))
+    $found=@([regex]::Matches($text,'D4R_NVAPI_TARGET=(gfx[0-9a-f]+)\0') | ForEach-Object { $_.Groups[1].Value } | Select-Object -Unique)
+    if ($found.Count -ne 1) { throw "NVAPI does not name exactly one GPU target (rebuild d4r_nvapi_compat): $Path" }
+    if ($found[0] -ne $Target) { throw "NVAPI is built for $($found[0]), not ${Target}: $Path" }
+}