add install video embed between pain points and dashboard demo

Author: weiyong1024

index.html

@@ -545,6 +545,18 @@ <h3>Self-hosting OpenClaw shouldn't be a nightmare.</h3>
     </div>
 </div>
 
+<!-- ── Install Video ─────────────────────────────── -->
+<section class="demo wrap">
+    <div class="demo-icon ic-green">
+        <svg width="48" height="48" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"><polygon points="5 3 19 12 5 21 5 3"/></svg>
+    </div>
+    <h2>Install in 30 seconds. Seriously.</h2>
+    <p class="demo-desc">One command. Docker auto-installed. Dashboard running. No config files touched.</p>
+    <div class="demo-frame" style="position:relative;padding-bottom:56.25%;height:0;overflow:hidden;">
+        <iframe src="https://www.youtube.com/embed/jE5ZR8g477s" style="position:absolute;top:0;left:0;width:100%;height:100%;border:0;border-radius:12px;" allowfullscreen></iframe>
+    </div>
+</section>
+
 <!-- ── Demo: Dashboard ───────────────────────────── -->
 <section class="demo wrap">
     <div class="demo-icon ic-blue">