curl --request PUT \
  --url https://api.gigabrain.gg/v1/superagents/{agent_id}/soul \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "soul_md": "<string>"
}
'

{
  "agent_id": "a1b2c3d4-5678-90ab-cdef-1234567890ab",
  "status": "updated"
}