Add DLSS accuracy mode and GLIBC 2.41 release builds

- Add default-off PreferAccuracy for all native kernel families,
  including RDNA4 FP8 variants.

- Restore intermediate FP8 quantization, per-MMA FP16 rounding,
  denormal handling and NGX synchronization in accuracy mode.

- Select separately marked accuracy kernels and use a separate JIT
  cache; reject mixed sets and never silently substitute fast kernels.

- Add a pinned GLIBC 2.41 build environment for ZLUDA/LLVM, the DLLs
  and both kernel sets, with ABI checks and toolchain provenance.

- Support parallel target builds and pre-extracted PTX; correct
  ROCm header paths and Clang-CL input handling.

- Bump to 0.1.3 and update release notes, documentation and tests.

Validation: 11 tests passed; all 912 kernels built; E/K/M GPU harness
runs completed with accuracy off/on. Packaged libraries loaded under
GLIBC 2.41 and require no GLIBC version newer than 2.38.

RTX image-quality parity remains unverified.

Fixes #6
Refs #6

config/d4r.ini.default

@@ -36,9 +36,15 @@ Model = K
 FrameAge = 0
 
 [Kernels]
+; Prefer NVIDIA's original arithmetic over speed for every native kernel and the translated fallback.
+; Restores intermediate FP8 quantization, per-MMA f16 rounding and original denormal handling; keeps
+; NGX's synchronizations. Selects accuracy variants in NativeKernelDir*/accuracy (or a marked accuracy
+; directory directly). Missing accuracy kernels use translated PTX, never the fast set. Slower; this
+; aims for fidelity, but RTX image parity is not proven. (D4R_PREFER_ACCURACY)
+PreferAccuracy = false
 ; Native RDNA3 / RDNA4 kernels for the DLSS 4 and 4.5 network layers (replace ZLUDA's translated code).
-;   fast  = native kernels with relaxed numerics (visually identical to exact, ~15% faster)
-;   exact = native kernels that reproduce NVIDIA's FP8/f16 rounding bit for bit
+;   fast  = native kernels with relaxed numerics (unless PreferAccuracy is true)
+;   exact = a separately built directory with conservative FP8/f16 rounding; not an RTX parity guarantee
 ;   off   = ZLUDA-translated kernels only
 ; fast/exact need the code objects built by the native-kernel tools ([Paths] NativeKernelDir*).
 NativeKernels = off