[Model] Support Qwen3-TTS model series (#895)

Signed-off-by: Gaohan123 <hgaoaf@connect.ust.hk>

docs/user_guide/examples/offline_inference/qwen3_tts.md

@@ -0,0 +1,94 @@
+# Qwen3-TTS Offline Inference
+
+Source <https://github.com/vllm-project/vllm-omni/tree/main/examples/offline_inference/qwen3_tts>.
+
+
+This directory contains an offline demo for running Qwen3 TTS models with vLLM Omni. It builds task-specific inputs and generates WAV files locally.
+
+## Model Overview
+
+Qwen3 TTS provides multiple task variants for speech generation:
+
+- **CustomVoice**: Generate speech with a known speaker identity (speaker ID) and optional instruction.
+- **VoiceDesign**: Generate speech from text plus a descriptive instruction that designs a new voice.
+- **Base**: Voice cloning using a reference audio + reference transcript, with optional mode selection.
+
+## Setup
+Please refer to the [stage configuration documentation](https://docs.vllm.ai/projects/vllm-omni/en/latest/configuration/stage_configs/) to configure memory allocation appropriately for your hardware setup.
+
+## Quick Start
+
+Run a single sample for a task:
+
+```
+python end2end.py --query-type CustomVoice
+```
+
+Generated audio files are saved to `output_audio/` by default.
+
+## Task Usage
+
+### CustomVoice
+
+Single sample:
+
+```
+python end2end.py --query-type CustomVoice
+```
+
+Batch sample (multiple prompts in one run):
+
+```
+python end2end.py --query-type CustomVoice --use-batch-sample
+```
+
+### VoiceDesign
+
+Single sample:
+
+```
+python end2end.py --query-type VoiceDesign
+```
+
+Batch sample:
+
+```
+python end2end.py --query-type VoiceDesign --use-batch-sample
+```
+
+### Base (Voice Clone)
+
+Single sample:
+
+```
+python end2end.py --query-type Base
+```
+
+Batch sample:
+
+```
+python end2end.py --query-type Base --use-batch-sample
+```
+
+Mode selection for Base:
+
+- `--mode-tag icl` (default): standard mode
+- `--mode-tag xvec_only`: enable `x_vector_only_mode` in the request
+
+Examples:
+
+```
+python end2end.py --query-type Base --mode-tag icl
+```
+
+## Notes
+
+- The script uses the model paths embedded in `end2end.py`. Update them if your local cache path differs.
+- Use `--output-dir` (preferred) or `--output-wav` to change the output folder.
+
+## Example materials
+
+??? abstract "end2end.py"
+    ``````py
+    --8<-- "examples/offline_inference/qwen3_tts/end2end.py"
+    ``````

docs/user_guide/examples/online_serving/text_to_image.md

@@ -119,6 +119,7 @@ Use `extra_body` to pass generation parameters:
 | `seed`                   | int   | None    | Random seed (reproducible)     |
 | `negative_prompt`        | str   | None    | Negative prompt                |
 | `num_outputs_per_prompt` | int   | 1       | Number of images to generate   |
+| `--cfg-parallel-size`.   | int   | 1       | Number of GPUs for CFG parallelism |
 
 ## Response Format