Add vLLM-Omni as a self-hosting option for Higgs Audio v3

Adds a vLLM-Omni Usage subsection alongside SGLang Usage. vLLM-Omni has first-class Higgs Audio v3 TTS support merged upstream (vllm-project/vllm-omni#4169, perf #4204), serving the same OpenAI-compatible /v1/audio/speech API with zero-shot voice cloning. Serve command mirrors the official vLLM-Omni recipe.

README.md

@@ -510,6 +510,27 @@ Throughput on Seed-TTS EN (full set, **N=1088** per run). Client `--max-concurre
 
 To reproduce the results, follow the instructions in [this script](https://github.com/sgl-project/sglang-omni/blob/main/benchmarks/eval/benchmark_tts_seedtts.py).
 
+### vLLM-Omni Usage
+
+You can also serve these weights with [**vLLM-Omni**](https://github.com/vllm-project/vllm-omni), which exposes the same OpenAI-compatible `/v1/audio/speech` API with zero-shot voice cloning.
+
+```bash
+hf download bosonai/higgs-audio-v3-tts-4b
+
+vllm-omni serve bosonai/higgs-audio-v3-tts-4b \
+  --host 0.0.0.0 --port 8095 \
+  --trust-remote-code --omni
+```
+
+```bash
+curl -X POST http://localhost:8095/v1/audio/speech \
+  -H "Content-Type: application/json" \
+  -d '{"model": "bosonai/higgs-audio-v3-tts-4b", "input": "Hello, how are you?"}' \
+  --output output.wav
+```
+
+Plain-text TTS, voice-clone, and benchmark recipes are in the [vLLM-Omni Higgs Audio v3 recipe](https://github.com/vllm-project/vllm-omni/blob/main/recipes/BosonAI/Higgs-Audio-V3-TTS.md).
+
 ### API Usage
 
 For zero-ops deployment, use the [**Boson AI API**](https://docs.boson.ai/models/higgs-audio-tts/overview).