curl --request PATCH \
  --url https://api.stardex.ai/v1/person-activities/{id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "activity_content": "This is plain text content",
  "content_type": "text"
}'

{
  "success": true,
  "data": {
    "id": "123e4567-e89b-12d3-a456-426614174000",
    "updated_at": "2024-03-15T12:00:00Z"
  }
}