docs(methods): add the summarize command to setCommands example

Match the three-command payload (create-pr / run-tests / summarize) on
the agents.conversations.setCommands docs page.

Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: 3 people

methods/src/agents/conversations/agents_conversations_set_commands.py

@@ -21,6 +21,10 @@
             "name": "run-tests",
             "description": "Run the test suite and report back",
         },
+        {
+            "name": "summarize",
+            "description": "Post a summary of the work so far",
+        },
     ],
 )