[BUG] LaTex format identification

[Junyi-99]

1. Modified the title, not sure why \title{} was also removed. For example \title{xxx} was changed to xxx

2. There is an issue with the handling of the percent sign. Specifically, GPT changed the LaTeX \% to %.

[4ndrelim]

Adding safeguards? Look into internal prompts.

[4ndrelim]

@wjiayis Might this be related to #160?

But this issue kinda suggest the text beyond % were not dropped, just that ... \% ... -> ... % .... I'll trace the overall logic / workflow, but tagging you to check if you are aware of the overall logic and could shed some light.