Add webAI app waitlist call to action; remove stray build artifacts

app.py

@@ -113,13 +113,16 @@ def _card_html(case: dict) -> str:
     )
 
 
-HEADER = """
+WAITLIST_URL = "https://www.webai.com/waitlist"
+
+HEADER = f"""
 <div class="twil-header">
   <img class="twil-mark" src="/gradio_api/file=brand/AppiCon.svg" alt="webAI" />
   <div class="twil-header-copy">
     <div class="twil-wordmark">webAI</div>
     <div class="twil-product">TwIL-LM3 · Intelligence Lab</div>
   </div>
+  <a class="twil-cta twil-cta-header" href="{WAITLIST_URL}" target="_blank" rel="noopener">Get early access</a>
 </div>
 """
 
@@ -136,11 +139,16 @@ document.addEventListener("keydown", (e) => {
 </script>
 """
 
-PLACEHOLDER = """
+PLACEHOLDER = f"""
 <div class="twil-empty">
   <img class="twil-cube" src="/gradio_api/file=brand/webai-cube-256.webp" alt="" />
   <h1>What should we work on?</h1>
   <p>TwIL-LM3 is webAI's formal-logic model — entailment, FOL, Lean, rule induction.</p>
+  <div class="twil-waitlist">
+    <p>TwIL and the full family of webAI models are coming to the webAI app.
+    Be the first to try expert intelligence on everyday devices.</p>
+    <a class="twil-cta" href="{WAITLIST_URL}" target="_blank" rel="noopener">Join the waitlist</a>
+  </div>
 </div>
 """
 
@@ -240,6 +248,43 @@ footer, .footer, .built-with, .settings, .settings-bar, .show-api,
 .twil-wordmark { font-weight: 600; font-size: 15px; letter-spacing: -0.02em; line-height: 1.2; color: var(--weba-fg); }
 .twil-product { font-size: 12px; color: var(--weba-muted); line-height: 1.3; }
 
+.twil-cta {
+  display: inline-flex;
+  align-items: center;
+  height: 34px;
+  padding: 0 18px;
+  border-radius: 999px;
+  background: var(--weba-primary);
+  color: var(--weba-primary-fg) !important;
+  font-size: 13px;
+  font-weight: 500;
+  text-decoration: none !important;
+  border: none;
+  white-space: nowrap;
+  transition: opacity 0.15s ease;
+}
+.twil-cta:hover { opacity: 0.85; }
+.twil-cta-header {
+  margin-left: auto;
+  height: 30px;
+  padding: 0 14px;
+  font-size: 12px;
+}
+.twil-waitlist {
+  margin-top: 28px;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 12px;
+}
+.twil-waitlist p {
+  margin: 0;
+  max-width: 30rem;
+  font-size: 13px;
+  line-height: 1.5;
+  color: var(--weba-muted);
+}
+
 .twil-empty {
   height: 100%;
   min-height: 280px;