fix: replace index-based React keys with stable data keys (F-9)

Use page paths, referrer URLs, item names, and composite location
keys instead of array indices. Prevents stale-row glitches when
lists are filtered or reordered.

app/faq/page.tsx

@@ -114,7 +114,7 @@ export default function FAQPage() {
 
         <div className="max-w-3xl mx-auto">
           {faqs.map((faq, index) => (
-            <FAQItem key={index} faq={faq} index={index} />
+            <FAQItem key={faq.question} faq={faq} index={index} />
           ))}
         </div>