Add QuestionsStatsPage component to display question statistics by category and difficulty. Update Navigation component to include a link to the new Questions page. Enhance question data in JSON files with additional entries for better coverage.

Author: smart-ex

app/questions/page.tsx

@@ -11,6 +11,7 @@ export function Navigation() {
   const links = [
     { href: '/', label: 'Home', icon: HomeIcon },
     { href: '/quiz', label: 'Quiz', icon: QuizIcon },
+    { href: '/questions', label: 'Questions', icon: QuestionsIcon },
     { href: '/stats', label: 'Stats', icon: StatsIcon },
   ];
 
@@ -141,6 +142,14 @@ function QuizIcon({ className }: { className?: string }) {
   );
 }
 
+function QuestionsIcon({ className }: { className?: string }) {
+  return (
+    <svg className={className} fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
+      <path strokeLinecap="round" strokeLinejoin="round" d="M8.228 9c.549-1.165 2.03-2 3.772-2 2.21 0 4 1.343 4 3 0 1.4-1.278 2.575-3.006 2.907-.542.104-.994.54-.994 1.093m0 3h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z" />
+    </svg>
+  );
+}
+
 function StatsIcon({ className }: { className?: string }) {
   return (
     <svg className={className} fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>