ggml: bump to qvac-ext-ggml#8 (Supertonic ops + Vulkan/Metal fixes)

[ogad-tether]

Summary

Updates the registry's ggml port pin from 05afdc59 (merge of qvac-ext-ggml#6) to 60a172e (merge of qvac-ext-ggml#8) — the head of the speech branch.

Bumps ggml port-version 7 → 8.

What's new in this bump

Between the prior pin (05afdc59) and the new one (60a172e), the speech branch picked up:

From qvac-ext-ggml#7 (merge 91676f0): Vulkan / Metal / CMake fixes cherry-picked from the 2026-01-30 branch — persistent VkPipelineCache + crash-safe eager flush, GGML_LIB_OUTPUT_PREFIX option, hybrid backend packaging, GGML_METAL_FUSE_MV_BIAS CMake option, std::filesystem pipeline-cache rename (Windows-correct overwrite).

From qvac-ext-ggml#8 (merge 60a172e): The Supertonic 2 fused custom op family — five fused Metal kernels (depthwise_1d / layer_norm_channel / pw2_residual / bias_gelu / edge_pad_1d), each with a CPU forward as parity backstop. Stride-parameterised so the same compiled Metal kernel handles both [T, C] and [C, T] activations via an op_params layout flag. New public ctors in ggml.h: ggml_supertonic_*{,_ct,_causal_ct}. GGML_OP_COUNT bumps 96 → 101.

Downstream consumer

qvac-ext-lib-whisper.cpp#15 (tts-cpp Supertonic Metal port) currently carries a local overlay-port to ship the supertonic patches. Once this lands, that PR can delete its entire tts-cpp/cmake/vcpkg-overlay-ports/ggml/ directory + the tts-cpp/vcpkg-configuration.json shim, and source the patched ggml directly from this registry.

Test plan

• vcpkg x-add-version ggml clean (added 2026-01-30#8 to versions/g-/ggml.json + versions/baseline.json)
• tts-cpp builds against this branch end-to-end on Apple M2 / Metal
• supertonic-cli writes a valid 2.85 s WAV at 44.1 kHz with all _ct paths engaged
• supertonic-bench: vocoder 13.88 ms / vec_est 63 ms / total 96 ms median (causal kernel active end-to-end via the upstream path)
• Reviewer to confirm no regression for non-Supertonic ggml consumers — all additions on the speech branch are net-new ops; no existing code paths modified

🤖 Generated with Claude Code

[ogad-tether]

Closing — the bump scope is too broad for this round.

The registry's ggml port is shared across many consumers (whisper-cpp, llama-cpp, qvac-fabric, …); bumping the pin from 05afdc59 to 60a172e brings in 9 commits (Vulkan/Metal/CMake fixes from qvac-ext-ggml#7 + the Supertonic ops from #8). Even though everything on the speech branch is additive (new ops, new CMake options), GGML_OP_COUNT changes 96 → 101 and the other tweaks could affect other consumers' builds in ways that haven't been validated here.

The downstream consumer (qvac-ext-lib-whisper.cpp#15) already uses a local overlay-port that sources directly from qvac-ext-ggml@speech HEAD 60a172e with zero patch files — the supertonic ops come in via the source commits, not via the registry. That keeps the blast radius scoped to tts-cpp.

We can revisit this bump as its own PR once other consumers have had a chance to validate against speech HEAD.

🤖 Generated with Claude Code