docs: update registry agents (#429)

Co-authored-by: benbrandt <2111074+benbrandt@users.noreply.github.com>

Author: acp-release-bot[bot]

docs/get-started/registry.mdx

@@ -248,7 +248,29 @@ Visit [the registry repository on GitHub](https://github.com/agentclientprotocol
       <code>2.0.1</code>
     </p>
   </Card>
-  <Card title="OpenCode" href="https://github.com/sst/opencode">
+  <Card
+    title="OpenCode"
+    href="https://github.com/sst/opencode"
+    icon={
+      <svg
+        width="20"
+        height="20"
+        className="agent-icon"
+        aria-hidden="true"
+        focusable="false"
+        viewBox="0 0 16 16"
+        fill="none"
+        xmlns="http://www.w3.org/2000/svg"
+      >
+        <path
+          fillRule="evenodd"
+          clipRule="evenodd"
+          d="M13 14H3V2H13V14ZM10.5 4.4H5.5V11.6H10.5V4.4Z"
+          fill="currentColor"
+        />
+      </svg>
+    }
+  >
     <p class="text-xs mt-3">
       <code>1.1.42</code>
     </p>