🧮 feat: Improve LaTeX rendering consistency (#3763)

* refactor: simplify LaTeX pre-processing for more consistent rendering, disables `singleDollarTextMath`

* refactor: disable singleDollarTextMath in all markdown components

* wip: first pass

* refactor: preserve code blocks and convert rather than preserve LaTeX delimiters

* refactor: remove unused escapeDollarNumber function from latex.ts

client/src/utils/latex.ts

@@ -40,3 +40,66 @@ export const processLaTeX = (_content: string) => {
   // Restore code blocks
   return restoreCodeBlocks(processedContent, codeBlocks);
 };
+
+/**
+ * Preprocesses LaTeX content by replacing delimiters and escaping certain characters.
+ *
+ * @param content The input string containing LaTeX expressions.
+ * @returns The processed string with replaced delimiters and escaped characters.
+ */
+export function preprocessLaTeX(content: string): string {
+  // Step 1: Protect code blocks
+  const codeBlocks: string[] = [];
+  content = content.replace(/(```[\s\S]*?```|`[^`\n]+`)/g, (match, code) => {
+    codeBlocks.push(code);
+    return `<<CODE_BLOCK_${codeBlocks.length - 1}>>`;
+  });
+
+  // Step 2: Protect existing LaTeX expressions
+  const latexExpressions: string[] = [];
+  content = content.replace(/(\$\$[\s\S]*?\$\$|\\\[[\s\S]*?\\\]|\\\(.*?\\\))/g, (match) => {
+    latexExpressions.push(match);
+    return `<<LATEX_${latexExpressions.length - 1}>>`;
+  });
+
+  // Step 3: Escape dollar signs that are likely currency indicators
+  content = content.replace(/\$(?=\d)/g, '\\$');
+
+  // Step 4: Restore LaTeX expressions
+  content = content.replace(/<<LATEX_(\d+)>>/g, (_, index) => latexExpressions[parseInt(index)]);
+
+  // Step 5: Restore code blocks
+  content = content.replace(/<<CODE_BLOCK_(\d+)>>/g, (_, index) => codeBlocks[parseInt(index)]);
+
+  // Step 6: Apply additional escaping functions
+  content = escapeBrackets(content);
+  content = escapeMhchem(content);
+
+  return content;
+}
+
+export function escapeBrackets(text: string): string {
+  const pattern = /(```[\S\s]*?```|`.*?`)|\\\[([\S\s]*?[^\\])\\]|\\\((.*?)\\\)/g;
+  return text.replace(
+    pattern,
+    (
+      match: string,
+      codeBlock: string | undefined,
+      squareBracket: string | undefined,
+      roundBracket: string | undefined,
+    ): string => {
+      if (codeBlock != null) {
+        return codeBlock;
+      } else if (squareBracket != null) {
+        return `$$${squareBracket}$$`;
+      } else if (roundBracket != null) {
+        return `$${roundBracket}$`;
+      }
+      return match;
+    },
+  );
+}
+
+export function escapeMhchem(text: string) {
+  return text.replaceAll('$\\ce{', '$\\\\ce{').replaceAll('$\\pu{', '$\\\\pu{');
+}