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.

engine/test_frame.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+"""Compare full native frame results, including the engine's own temporal feedback.
+
+test_frame.py CASE_DIR RESULT_DIR [--min-psnr 50]
+Exits nonzero for missing data, nonfinite output, or a PSNR regression.
+"""
+import argparse
+import json
+from pathlib import Path
+import numpy as np
+
+
+def compare(reference, output):
+    a = np.fromfile(reference, np.float16).astype(np.float64)
+    b = np.fromfile(output, np.float16).astype(np.float64)
+    if a.shape != b.shape or not a.size:
+        raise ValueError(f'{output}: size differs from reference')
+    if not np.isfinite(a).all() or not np.isfinite(b).all():
+        raise ValueError(f'{output}: nonfinite reference or result')
+    error = np.abs(a - b)
+    peak = max(np.abs(a).max(), 1e-9)
+    psnr = 10 * np.log10(peak**2 / max((error**2).mean(), 1e-30))
+    return psnr, error.max(), error.mean()
+
+
+def main():
+    p = argparse.ArgumentParser(description=__doc__)
+    p.add_argument('case', type=Path)
+    p.add_argument('results', type=Path)
+    p.add_argument('--min-psnr', type=float, default=50)
+    a = p.parse_args()
+    references = json.loads((a.case / 'references.json').read_text())
+    if not references: raise ValueError('no reference frames')
+    failed = False
+    names = {'288': 'history color', '296': 'hi-res luma', '304': 'token feature', '312': 'final RGB'}
+    for i, refs in enumerate(references):
+        for off, reference in refs.items():
+            psnr, maximum, mean = compare(reference, a.results / f'frame-{i}.{off}.bin')
+            print(f'frame {i} {names[off]:14s}: {psnr:6.1f} dB PSNR; max error {maximum:.5g}; mean {mean:.5g}')
+            failed |= psnr < a.min_psnr
+    if failed: raise SystemExit(f'frame validation failed: PSNR below {a.min_psnr:g} dB')
+
+
+if __name__ == '__main__': main()