Migrate to MathML-compatible LaTeX math

As of now, great part of the math in the ebook cannot be converted to MathML. It would be nice to be able to use it for visually-impaired people as well as more modern ereaders, instead of the SVG output from gladtex.

The issue is about converting LaTeX math in an ebook to be MathML-compatible, likely for accessibility. First, examine the current build pipeline (possibly involving gladtex) to understand how math is currently processed. Look for LaTeX source files or configuration. Research MathML compatibility requirements and test conversion tools. The goal is to produce output that works with screen readers and modern ereaders.

由索引模型根据 Issue 内容生成。