Add link to AdCP schema tool (prebid#6519)

Updated the link to the testing dashboard and clarified the repository reference.

Author: ChrisHuie

agents/salesagent.md

@@ -10,7 +10,7 @@ sidebarType: 10
 The Prebid Sales Agent is a server that exposes advertising inventory to AI agents via the Model Context Protocol (MCP) and Agent-to-Agent (A2A) protocol. It is designed to integrate with ad servers like Google Ad Manager and provides tools for managing inventory and campaigns throughout their lifecycle.
 
 <div class="alert alert-info" role="alert">
-  For the full source code and latest updates, visit the <a href="https://github.com/prebid/salesagent">prebid/salesagent repository</a>.
+  Please see our Prebid Salesagent <a href="https://main.d1tyvbf1at6iao.amplifyapp.com">testing dashboard</a> for feature and schema testing coverage or visit the <a href="https://github.com/prebid/salesagent">salesagent repository</a>.
 </div>
 
 ## Key Features