When editing reports, tiptap-markdown escapes special characters (*, _, [, ])
which corrupts LaTeX formulas. This fix:
1. Adds unescapeLatexInMath() function to reverse markdown escaping within
math delimiters ($...$ and 94410...94410)
2. Applies the unescape function in the editor's onChange callback to clean
the markdown before storing it
3. Adds comprehensive tests covering edge cases and round-trip scenarios
The fix ensures formulas like $(f * g)[n]$ remain unescaped when editing,
preventing display errors after save/reload.