[BUG] [UI] <title>Markdown/code block rendering broken in chat

[pepeyc7526]

是否已有关于该错误的issue或讨论？ | Is there an existing issue / discussion for this?

• 我已经搜索过已有的issues和讨论 | I have searched the existing issues / discussions

该问题是否在FAQ中有解答？ | Is there an existing answer for this in FAQ?

• 我已经搜索过FAQ | I have searched FAQ

当前行为 | Current Behavior

Subject: Formatting issue in chat interface

Description:
The chat interface sometimes breaks markdown and code blocks into fragmented lines, making it hard to read commands or code examples.

Example:
Instead of rendering this as a proper code block:

git pull origin main

### 期望行为 | Expected Behavior


---

### ✅ **Expected Behavior**  
```markdown
Code blocks and markdown lists should render as formatted blocks with correct syntax highlighting and indentation, exactly as written in the response.

### 复现方法 | Steps To Reproduce

1. Ask Qwen to provide a command or code snippet wrapped in ```bash or ```python.
2. Observe how the response is displayed in the chat UI.
3. Note that code blocks appear as unformatted, fragmented text instead of properly enclosed blocks.

### 运行环境 | Environment

```Markdown
- OS: Ubuntu 26.04
- Browser: Brave 1.86.142 (Official Build) (64-bit) Chromium: 144.0.7559.97
- Device: Laptop 
- Qwen version: Web UI Qwen3-Max

备注 | Anything else?