docs: add audio.cpp to Ecosystem & Community (EN/ZH) (#355)

Add audio.cpp (ggml-based unified C++ inference framework) to the
Ecosystem & Community table in both README.md and README_zh.md.
VoxCPM2 is a released, supported model in that project.

Requested in #354.

Co-authored-by: Labmem-Zhouyx <913703649@qq.com>

README.md

@@ -628,6 +628,7 @@ Full documentation: **[voxcpm.readthedocs.io](https://voxcpm.readthedocs.io/en/l
 | **[vLLM-Omni](https://github.com/vllm-project/vllm-omni)**                  | Official vLLM omni-modal serving for VoxCPM2 — PagedAttention, OpenAI-compatible API             |
 | **[llama.cpp-omni](https://github.com/tc-mb/llama.cpp-omni)**               | Full-duplex omni inference engine — VoxCPM2 GGUF on CPU / Metal / CUDA / Vulkan                   |
 | **[VoxCPM.cpp](https://github.com/bluryar/VoxCPM.cpp)**                     | GGML/GGUF: CPU, CUDA, Vulkan inference                                                           |
+| **[audio.cpp](https://github.com/0xShug0/audio.cpp)**                       | ggml-based unified C++ inference framework — CPU/CUDA/Vulkan/Metal, CLI & server, no Python      |
 | **[VoxCPM-ONNX](https://github.com/bluryar/VoxCPM-ONNX)**                   | ONNX export for CPU inference                                                                    |
 | **[VoxCPMANE](https://github.com/0seba/VoxCPMANE)**                         | Apple Neural Engine backend                                                                      |
 | **[voxcpm_rs](https://github.com/madushan1000/voxcpm_rs)**                  | Rust re-implementation                                                                           |

README_zh.md

@@ -618,6 +618,7 @@ python lora_ft_webui.py   # 然后打开 http://localhost:7860
 | [**vLLM-Omni**](https://github.com/vllm-project/vllm-omni) | 官方 vLLM 全模态服务（原生支持 VoxCPM2）— PagedAttention、OpenAI 兼容 API |
 | [**llama.cpp-omni**](https://github.com/tc-mb/llama.cpp-omni) | 全双工全模态推理引擎 — VoxCPM2 GGUF，支持 CPU / Metal / CUDA / Vulkan |
 | [**VoxCPM.cpp**](https://github.com/bluryar/VoxCPM.cpp) | GGML/GGUF：CPU、CUDA、Vulkan 推理 |
+| [**audio.cpp**](https://github.com/0xShug0/audio.cpp) | 基于 ggml 的统一 C++ 推理框架 — CPU/CUDA/Vulkan/Metal，CLI 与服务端，无需 Python |
 | [**VoxCPM-ONNX**](https://github.com/bluryar/VoxCPM-ONNX) | ONNX 导出，支持 CPU 推理 |
 | [**VoxCPMANE**](https://github.com/0seba/VoxCPMANE) | Apple Neural Engine 后端 |
 | [**voxcpm_rs**](https://github.com/madushan1000/voxcpm_rs) | Rust 重新实现 |