Fix checkout links to absolute URLs

index.html

@@ -572,7 +572,7 @@
       <!-- Pro upsell (shown when quota exhausted) -->
       <div class="pro-bar" id="pro_bar" style="display:none">
         <div class="pro-bar-icon">💎</div>
-        <div>Out of free estimates today. <strong>Get unlimited for $5/month</strong> — <a href="/loomlensai-pro.html" target="_blank">Upgrade Now</a></div>
+        <div>Out of free estimates today. <strong>Get unlimited for $5/month</strong> — <a href="https://signalloom-landing.pages.dev/loomlensai-pro.html" target="_blank">Upgrade Now</a></div>
       </div>
 
       <button class="btn-estimate" id="btn_estimate" onclick="runEstimate()">Estimate Cost</button>