v0.2.1

Changes

• Protect TeX backslashes and LaTeX braces — protectMath now protects backslashes (\) inside math formulas (MATH_BACKSLASH_SUB), preventing CommonMark parsers from stripping backslashes before markdown characters like \{, \}, or collapsing double backslashes \\ in matrices and aligned equations.
• Fix multiline block closing delimiter — mathBlockExtension now recognizes $$ at the end of a line even when attached directly to code without preceding whitespace (e.g. \end{aligned}$$ or \end{matrix}$$), preventing block fences from swallowing subsequent lines.