8a1d0bf709
s2.cpp's README example uses `-v 0` which is `--vulkan 0` (Vulkan device 0), easy to misread as "voice 0". The shim copied that verbatim, so even after fixing the libcuda.so build problem AND the libgomp.so runtime dep, every synthesis ran on CPU because the wrong backend was selected. Direct verification: `[Model] NPU not compiled, falling back to CPU` in stderr; nvidia-smi showed no s2 process; bench timed out at 60s on phrases that fish-s2 (HF, GPU) does in 7s. s2.cpp's CLI: -v <id> = --vulkan <device> -c <id> = --cuda <device> -M = --metal (Apple Silicon) Switched the shim to `-c 0`. The CUDA backend IS in the build (-DS2_CUDA=ON worked, libggml-cuda.so links fine per ldd, libcuda.so.1 mounts at runtime via NVIDIA container runtime) — just wasn't being told to use it.