use new banner functionality for Agent announcement

Author: JTorreG

_banners/agent-v3-release.md

@@ -0,0 +1,7 @@
+{{< banner "notice" "NGINX Agent v3.0 is now available" >}}
+
+ This documentation is for **NGINX Agent v2**. Visit the [Update NGINX Agent]({{< ref "/nginx-one/agent/install-upgrade/update.md" >}}) topic to learn how to upgrade your instances to the latest version.
+
+ For NGINX Agent v3 documentation, visit the [NGINX One Console docs]({{< ref "/nginx-one/agent/" >}}).
+
+{{< /banner >}}

content/agent/_index.md

@@ -5,5 +5,10 @@ description: NGINX Agent is a companion daemon for your NGINX Open Source or NGI
 url: /nginx-agent/
 cascade:
   logo: NGINX-product-icon.png
-  type: agent-v2-migration
+  banner:
+    enabled: true
+    type: deprecation
+    start-date: 2025-05-29
+    end-date: 2025-09-09
+    md: /_banners/agent-v3-release.md
 ---