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

engine/rr/rr_capture.py

@@ -70,16 +70,20 @@ class Launch:
     def image(self, offset):
         return next(i for i in self.images if i.offset == offset)
 
+    def weights_at(self, offset):
+        """the weight image (the pointer at argument OFFSET) as NGX uploaded it; 16 zero bytes for a stage without one"""
+        pointer = next((p for p in self.pointers if p.offset == offset), None)
+        return self.pre(pointer.alloc) if pointer is not None else bytes(16)
+
     @property
     def weights(self):
-        """the weight image (argument 40) as NGX uploaded it; 16 zero bytes for a stage without one (the output stage)"""
-        pointer = next((p for p in self.pointers if p.offset == 40), None)
-        return self.pre(pointer.alloc) if pointer is not None else bytes(16)
+        """the DLSS-D kernels' weight image (argument 40)"""
+        return self.weights_at(40)
 
     @property
     def arena_alloc(self):
         """the plane arena: the allocation every arena pointer of the layer points into"""
-        candidates = [p.alloc for p in self.pointers if p.offset != 40]
+        candidates = [p.alloc for p in self.pointers]
         return max(set(candidates), key=lambda a: self.allocs[a][1]) if candidates else None
 
     def post_buffer(self, capture, alloc):