The page's composer (its input, slash commands and completion), POST /send in
hive-agent, the OperatorMsg request of the agent socket and its handler in
hive-c0re, and the broker-error helper only the send route used are deleted:
writing to an agent is the swarm UI's terminal. cancel turn, new session and
log out stay in the state badge's menu; POST /api/compact stays, with nothing
on the page calling it. The request-line limit keeps its size, and its comment
says it is a generous bound now. The docs describe the actions in place of the
footer and the prompt.