curl --request PUT \
  --url http://localhost:8080/api/workspaces/{id}/task-agent-prompt \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "system_prompt": "<string>"
}
'

{
  "system_prompt": "<string>",
  "is_default": true
}