Registration now requires the password twice, rejected client-side on mismatch before hitting the API. The admin page gets a Utenti card: loads the user list (id, username, address, balance in PLM) and a per-row "Mostra" button that reveals the private key after an explicit confirm() — click again to hide it. A persistent warning banner notes that every reveal is audit-logged. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>