Add CUDA NGX Ray Reconstruction support

Run the signed CUDA-capable denoiser through feature 13 with independent D/E presets, pre-Init discovery, per-frame guide and camera snapshots, normalized integer guide staging, paired alpha output, and recorded-resource retirement.

Add the required ZLUDA/LLVM patch, behavioral configuration tests, GPU harness coverage, optional denoiser installation and packaging, and tested support limitations. Preserve upstream attribution and distinguish LLVM licensing from the ZLUDA portions of the patch.

scripts/d4r_config.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+# Modified in this fork for CUDA Ray Reconstruction support and validation (2026).
 """Translate d4r.ini (see config/d4r.ini.default) into shell exports for the game launcher.
 
 usage: d4r_config.py [--config PATH] [--print | --launch]
@@ -86,6 +87,20 @@ def main(argv):
         else:
             fail(f"[DLSS] Model {model!r}: use one of {', '.join(list(PRESETS) + list(MODEL_ALIASES))} or a preset number")
 
+    rr_enabled = flag("RayReconstruction", "Enable")
+    if rr_enabled is not None:
+        env["D4R_RR_ENABLE"] = "1" if rr_enabled else "0"
+    rr_model = get("RayReconstruction", "Model")
+    if rr_model is not None:
+        rr_presets = {"DEFAULT": 0, "D": 4, "E": 5}
+        rr_model = rr_model.upper()
+        if rr_model in rr_presets:
+            env["D4R_RR_PRESET"] = str(rr_presets[rr_model])
+        elif rr_model in ("0", "4", "5"):
+            env["D4R_RR_PRESET"] = rr_model
+        else:
+            fail(f"[RayReconstruction] Model {rr_model!r}: use auto, default, D or E")
+
     age = get("Latency", "FrameAge")
     if age is not None:
         if age not in ("0", "1", "2", "3"):