format of raw string literal   is incrrect

### Version

C# REPL 0.6.7+d2955f13e744320cd6331c484e1286c3ed4f8612

### What happened?

<img width="1049" height="267" alt="Image" src="https://github.com/user-attachments/assets/72a1ad14-199f-48be-b826-1b5757535a25" />

the json is actually  flow line
```C# 
var json = JsonSerializer.Deserialize<G>("""
  { "a":123, "b":"AAA"
  }
  """)

```