Add links to platform

app.py

@@ -955,7 +955,9 @@ def format_challenge_card(challenge: Dict) -> str:
         <div style='position:absolute;top:0;left:0;right:0;height:4px;background:linear-gradient(90deg,{card_border},transparent);'></div>
         
         <div style='display:flex;justify-content:space-between;align-items:flex-start;margin-bottom:20px'>
-            <h3 style='margin:0;color:#2c3e50;font-size:1.4em;font-weight:700;line-height:1.3;max-width:70%;'>{challenge['title']}</h3>
+            <h3 style='margin:0;color:#2c3e50;font-size:1.4em;font-weight:700;line-height:1.3;max-width:70%;'>
+                <a target="_blank" href="https://topcoder.com/challenges/{challenge['id']}?utm_source=huggingface&utm_medium=Topcoder">{challenge['title']}</a>
+            </h3>
             <div style='text-align:center;min-width:120px;'>
                 <div style='background:{score_color};color:white;padding:12px 18px;border-radius:30px;font-weight:700;font-size:1.1em;box-shadow:0 4px 12px rgba(0,0,0,0.15);'>{score:.0f}%</div>
                 <div style='color:{score_color};font-size:0.85em;margin-top:6px;font-weight:600;'>{score_label}</div>