weired dash in references

In the abstract body text (jason file) I got "... clock$^3$$^−$$^5$". This persists after running gca-tex on it. pdflatex then breaks:
```
! Missing { inserted.

\begingroup
l.105 ... They exhibit a circatidal clock$^3$$^−
$$^5$ plays a role in thei...
```
If I replace the dash (which is not a normal dash) by a normal dash or by `{--}` it works.

从对 JSON 输入中的摘要正文文本进行 gca-tex 处理开始，跟踪非标准破折号如何输出到 LaTeX。使用报告中的文本通过 pdflatex 重现该故障，然后验证生成的输出能够处理该破折号，而不会出现插入的错误 Missing { inserted。

由索引模型根据 Issue 内容生成。