updated chat agent

Author: soheimam

docs/wallet-app/guides/chat-agents.mdx

@@ -156,7 +156,7 @@ npm run dev
 XMTP_ENV=production
 ```
 
-2. Test on Coinbase Wallet:  
+2. Test on Base App:  
 • Open Base Appmobile app  
 • Go to messaging  
 • Start conversation with your agent's address