engine/rr: native preset F (DLSS 4.5 Ray Reconstruction) and the reference's fused roundings

- engine/compile_rr2.py, runtime_rr2.inc, engine/rr/rr2_m.comp, exposure_f.comp,
  gen_rr2_enc0.py, rr2_pack.py, rr2_ref.py: the rr2_* model (nvngx_dlssd.dll 310.9's
  third network) as d4r's own shaders - exposure, enc0 gather/block split, enc1-5 and
  dec4-0 through one matrix shader, translated output passes; weights packed from the
  DLL, argument blocks from the capture
- ptx2rr: match the driver's fused roundings - opaque-zero OR around cvt.rn.f16.f32
  against v_fma_mix, half-away-from-zero formatted stores, UNORM 10:10:10:2 as RGBA32F
  of q/1023, OCML tanhF with the AMDGPU exp lowering, binary16 fma and fetch roundings;
  --probe for register bisection against ZLUDA
- dec0_m/swin_m/enc0_*: RR_MIX build option (D4R_RR_MIX=1), one v_fma_mix rounding per
  32-deep step, ~5% faster, not bit-exact; default build stays exact
- runtime_rr.inc: RModel/REngine dispatch to the D4RR0002 model; replay_rr: RGBA32F and
  A2B10G10R1010 texel sizes, roughnessPacked bit, larger debug staging
- shim: engine\rr-f model slot, 310.9 version probe so preset F is only claimed when the
  CUDA path has it; d4r.ini / d4r_config.py Model = F; run_rr_engine_compare.sh D4R_RR_DLL
- kernels/rr/swin_native.h + rr_swin_native_test.cpp: HIP port of encoder 1 for the
  FP8-product and rounding cost measurements
- engine/rr/README: preset F's block, options, capture-by-capture results, timings and
  the open camera-matrix difference

tests/test_ray_reconstruction.py

@@ -44,8 +44,13 @@ class RayReconstructionConfigTests(unittest.TestCase):
         self.assertEqual(decided["D4R_RR_PRESET"], "5")     # Ray Reconstruction preset E
         self.assertEqual(decided["D4R_DLSS_PRESET"], "11")  # Super Sampling preset K
 
+    def test_dlss_45_ray_reconstruction_is_model_f(self):
+        code, decided = run_config("[RayReconstruction]\nEnable = true\nModel = F\n")
+        self.assertEqual(code, 0)
+        self.assertEqual(decided["D4R_RR_PRESET"], "6")     # preset F: nvngx_dlssd.dll 310.9 or later
+
     def test_invalid_rr_settings_are_rejected_rather_than_guessed(self):
-        for text in ("[RayReconstruction]\nModel = F\n",
+        for text in ("[RayReconstruction]\nModel = G\n",
                      "[RayReconstruction]\nModel = K\n",
                      "[RayReconstruction]\nEnable = maybe\n"):
             with self.subTest(ini=text):