Reword guest CTA: free for longer when signed in

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

index.html

@@ -1053,7 +1053,7 @@ pre {
     <!-- Guest CTA (shown when logged out) -->
     <div class="guest-cta" id="guest-cta" style="display:none">
       <div class="guest-cta-title">You're in guest mode</div>
-      <div class="guest-cta-sub">3 free runs to try it out. Sign in with Hugging Face for the full free ZeroGPU quota.</div>
+      <div class="guest-cta-sub">3 signed-out free runs. Sign in with Hugging Face to keep using it free for longer.</div>
       <button class="btn-hf btn-hf-sm guest-cta-btn" onclick="login()">🤗 Sign in with Hugging Face</button>
     </div>