[Bug] Runtime: LLM Cannot Complete Thought Process

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

[nodes_textgen.py](https://github.com/Comfy-Org/ComfyUI/blob/master/comfy_extras/nodes_textgen.py) The max length of 2048 is too short, the new think toggle cannot complete its thought if enabled. Requesting to change max length greater than 8192 or allow user to enter it manually instead of using a slider.

### Actual Behavior

[nodes_textgen.py](https://github.com/Comfy-Org/ComfyUI/blob/master/comfy_extras/nodes_textgen.py) Though process gets cut off due to hard limitation in length, it could not complete it though to produce result text.

### Steps to Reproduce

Enter this in the prompt and provide lyrics:

"將這些歌詞的核心主題與情感，濃縮成一個連貫且統一的提示詞，用於專輯封面圖像生成器。提示詞必須忠於歌詞的故事線，確保每個視覺元素皆源自於歌詞描述，並將以繁體中文撰寫的提示詞置於英文雙引號（" "）內，而非其他引號符號（例如不得使用「」）。提示詞需具體呈現歌詞故事中的視覺元素，如角色性別、服裝時尚、交通工具、環境場景、建築物、整體氛圍、色彩基調、時代或地點設定、藝術風格、歌詞描述的角色手勢與表情、角色的適當位置與構圖，以及能與歌曲情感相匹配的連貫圖像與光線照明。此外，所有與此任務相關的內部思考、分析或推理過程（例如 或 區塊、思考步驟、推理筆記等）均必須全程使用繁體中文撰寫，嚴禁使用任何英文單字或句子。亦即，AI 在產生最終提示詞之前的所有內部思維運算，都必須以繁體中文進行。

Lyrics:

"

### Debug Logs

```powershell
think process text overflow, causing think process to not complete.
```

### Other

qwen_2.5_vl_7b model