fix: broaden TOC removal to catch plain "Contents" text in any element

61 problems have TOC blocks. Now removes any leaf element whose only
text is "Contents" regardless of tag type, not just headings.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: andrewboldi

src/lib/utils/katex.ts

@@ -71,10 +71,12 @@ export function renderLatexInContainer(container: HTMLElement): void {
 	for (const toc of tocElements) {
 		toc.remove();
 	}
-	// Also remove any "Contents" text/heading that precedes a TOC list
+	// Remove any element whose only text content is "Contents"
+	// (may be a heading, div, span, or other wrapper)
 	const allElements = container.querySelectorAll('*');
 	for (const el of allElements) {
-		if (el.textContent?.trim() === 'Contents' && el.tagName.match(/^H[1-6]$/)) {
+		const text = el.textContent?.trim();
+		if (text === 'Contents' && el.children.length === 0) {
 			el.remove();
 		}
 	}