acp: Add a basic test for ACP remoting (#38381)

Tests that the downstream project can see custom agents configured in
the remote server's settings, and that it constructs an appropriate
`AgentServerCommand`.

Release Notes:

- N/A
eaa1cb0ca3Cole Miller committed on 9/18/2025, 4:02:44 AM· committed by GitHubparentea473ee
4 files changedLine totals unavailable