[FEAT] Simulazioni Demo + Audit Trail Certificato SHA-256

- 5 scenari reali: Onboarding, Ransomware Art.23, Data Breach Supply Chain,
  Whistleblowing SCADA, Audit Hash Chain Verification
- simulate-nis2.php: 3 aziende (DataCore/MedClinic/EnerNet), 10 fasi, CLI+SSE
- AuditService.php: hash chain SHA-256 stile lg231 (prev_hash+entry_hash)
- Migration 010: prev_hash, entry_hash, severity, performed_by su audit_logs
- AuditController: GET chain-verify + GET export-certified
- reset-demo.sql: reset dati demo idempotente
- public/simulate.html: web runner SSE con console dark-theme
- Sidebar: link Simulazione Demo + Integrazioni

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/js/common.js

@@ -213,6 +213,8 @@ function loadSidebar() {
             items: [
                 { name: 'Impostazioni', href: 'settings.html',     icon: iconCog(),             i18nKey: 'nav.settings' },
                 { name: 'Architettura', href: 'architecture.html', icon: iconCubeTransparent() },
+                { name: 'Simulazione Demo', href: 'simulate.html', icon: `<svg viewBox="0 0 20 20" fill="currentColor"><path fill-rule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM9.555 7.168A1 1 0 008 8v4a1 1 0 001.555.832l3-2a1 1 0 000-1.664l-3-2z" clip-rule="evenodd"/></svg>` },
+                { name: 'Integrazioni', href: 'integrations/index.html', icon: `<svg viewBox="0 0 20 20" fill="currentColor"><path d="M11 3a1 1 0 100 2h2.586l-6.293 6.293a1 1 0 101.414 1.414L15 6.414V9a1 1 0 102 0V4a1 1 0 00-1-1h-5z"/><path d="M5 5a2 2 0 00-2 2v8a2 2 0 002 2h8a2 2 0 002-2v-3a1 1 0 10-2 0v3H5V7h3a1 1 0 000-2H5z"/></svg>` },
             ]
         }
     ];