Add Reachy Mini animated GIF to main page hero section

Replace text architecture diagram with animated GIF showing the robot
in action for a more engaging visual on the Space landing page.

index.html

@@ -42,20 +42,9 @@
         </div>
         <div class="hero-visual">
             <div class="glass-card">
-                <div class="architecture-preview">
-<pre>
-  You speak → Reachy Mini 🎤
-          (or Simulator 🖥️)
-                  ↓
-         OpenAI Realtime API
-      (speech recognition + TTS)
-                  ↓
-          OpenClaw Gateway
-        (Clawson's brain 🦞)
-                  ↓
-     Robot speaks & moves 🤖💃
-</pre>
-                </div>
+                <img src="https://huggingface.co/spaces/pollen-robotics/reachy_mini_conversation_app/resolve/main/docs/assets/reachy_mini_dance.gif" 
+                     alt="Reachy Mini Robot Dancing" 
+                     class="hero-gif">
                 <p class="caption">Works with physical robot OR MuJoCo simulator!</p>
             </div>
         </div>

style.css

@@ -210,6 +210,15 @@ a {
     backdrop-filter: blur(10px);
 }
 
+.hero-gif {
+    width: 100%;
+    max-width: 500px;
+    height: auto;
+    border-radius: 14px;
+    display: block;
+    margin: 0 auto;
+}
+
 .architecture-preview {
     background: rgba(0, 0, 0, 0.4);
     border-radius: 14px;