ci: add tag-driven prebuilt release pipeline

[drzsdrtfg]

Summary

Adds the prebuilt release pipeline: every v* release now ships ready-to-run binaries attached to the GitHub Release. This is the full set of changes this fork adds over upstream 0xShug0/audio.cpp — 2 files.

Changes

File	What it does
.github/workflows/release.yml	Tag-driven release build + publish
docs/RELEASING.md	Release / dry-run / verification docs

.github/workflows/release.yml

• Triggers on a v* semver tag push, or manual workflow_dispatch with a publish checkbox (used for build-only dry runs). No release on every main push.
• Builds audiocpp_cli, audiocpp_server, audiocpp_gguf with -DAUDIOCPP_DEPLOYMENT_BUILD=ON -DENGINE_ENABLE_LLAMAFILE=ON -DENGINE_ENABLE_CUDA_GRAPHS=ON.
• Matrix (fail-fast off): macOS metal (arm64/x64), Ubuntu x64 cpu+vulkan, Windows x64 cpu+vulkan+cuda (12.4/13.3). linux-rocm is commented out (no AMD GPU runner).
• Windows CUDA uses GGML_BACKEND_DL: thin shells + a single ggml-cuda.dll; the CUDA runtime ships once in a separate -cudart-...zip. CUDA archs are pinned all-real.
• Assets: audio-<tag>-bin-windows-x64-<backend>.zip (+ -cudart-...zip); Linux/macOS as .tar.gz.
• Release job: gh release upload to an existing release (--clobber) or gh release create on a new tag (--generate-notes).

docs/RELEASING.md

UI-only steps to draft a release, tag, dry-run from the Actions tab, plus the artifact table and the GPU-runtime verification note.

Validation

The prebuilt binaries were downloaded and run to confirm they work out of the box.

Hardware:

• GPU: Radeon RX Vega 56 (Vulkan device: "Radeon RX Vega"; fp16:1, bf16:0, int dot:0, matrix cores:none, warp:64, 32 KB smem), 8 GB VRAM
• CPU: Intel Core i5-10400 (6c/12t), Windows, AMD proprietary driver

Config: audiocpp_cli --task tts --family supertonic --model supertonic-3-f16.gguf --voice-id M1 --num-inference-steps 8 --seed 1234

Vulkan binary (Radeon RX Vega 56):

Sample	Audio (s)	Gen wall (s)	RTF	x real-time
Short	5.02	1.80	0.359	2.79x
Medium	27.26	1.70	0.062	16.06x
Long	76.09	5.08	0.067	14.97x

CPU binary (i5-10400):

Threads	Audio (s)	Gen wall (s)	RTF	x real-time
1	13.57	18.98	1.398	0.72x
4	27.28	10.67	0.391	2.56x
10	74.25	21.74	0.293	3.42x

These runs only confirm the shipped binaries enumerate the device and synthesize correctly; see the README for reference performance figures.

Notes

• release.yml references macos-26 / macos-15-intel runner labels; adjust to this repo's runner pool if different.
• ROCm is disabled by default (no AMD runner); enable via self-hosted HIP runners.
• Optional follow-up: add a CI check job that runs the shipped Windows binaries.
• No runtime/model changes; CI and docs only.
• This PR's code and description were written and assisted by DeepSeek-V4-Flash-0731 through Cline.

[drzsdrtfg]

btw I dont know whether the other binaries work pls test them out on my fork before you merge this

[0xShug0]

@drzsdrtfg Thank you for the PR! It may require some time to test...Stay tuned.

[drzsdrtfg]

Ok. Just let me know when issues appear. @0xShug0