### wai-quantum 0.4.4: the fabric's CUDA member

Additive. The default features, `full`, and every pinned digest are unchanged.

- **The CUDA member** (`quantum_fabric_cuda`, opt-in, native targets only): the gate
  kernel in CUDA C with exact 64-bit integers, compiled at run time by the runtime
  compiler for each device's own architecture (`--fmad=false`), one launch per gate. The
  driver and the compiler are loaded when first used, so a build with the feature runs on
  a host without CUDA and finds no member there, saying why. Each device is probed against
  the CPU's arithmetic and certified bit-exact by reproducing the pinned corpus digests; a
  result that would leave 32 bits is refused, never returned.
- **CI.** `wai-quantum-cuda.yml`: the device tests on a hardware host's GPU (every
  certificate, every kernel mutant caught), and the same build on a host with no CUDA.

