fix(highlights): remove existing highlight marks before applying new ones

- Strip all existing mark elements from HTML before re-highlighting
- Prevents old broken highlights from persisting in the DOM
- Ensures clean text is used as the base for new highlight application
- Fixes 'We b' spacing issue caused by corrupted marks from previous buggy renders
- Remove debug logging now that position mapping is working correctly

src/utils/highlightMatching/htmlMatching.ts

@@ -22,6 +22,17 @@ export function applyHighlightsToHTML(
   const tempDiv = document.createElement('div')
   tempDiv.innerHTML = html
   
+  // CRITICAL: Remove any existing highlight marks to start with clean HTML
+  // This prevents old broken highlights from corrupting the new rendering
+  const existingMarks = tempDiv.querySelectorAll('mark[data-highlight-id]')
+  existingMarks.forEach(mark => {
+    // Replace the mark with its text content
+    const textNode = document.createTextNode(mark.textContent || '')
+    mark.parentNode?.replaceChild(textNode, mark)
+  })
+  
+  console.log('🧹 Removed', existingMarks.length, 'existing highlight marks')
+  
   let appliedCount = 0
   
   for (const highlight of highlights) {