feat: Dashboard frontend estilo JumpCloud

- Componente MainDashboard.jsx completo (400+ linhas)
- 5 cards de estatísticas principais
- 8 cards de alertas e notificações
- Status do sistema em tempo real
- Atualização automática a cada 30 segundos
- Design responsivo (mobile, tablet, desktop)
- Rota backend /api/dashboard/stats
- Documentação completa (FRONTEND_DASHBOARD.md)
- Paleta de cores similar ao JumpCloud
- Integração com sistema MDM

Dashboard moderno e funcional pronto para uso!

backend/routes/dashboard.js

@@ -126,5 +126,80 @@ router.get('/', authenticateToken, async (req, res) => {
     }
 });
 
+// GET /api/dashboard/stats - Estatísticas expandidas para o novo dashboard
+router.get('/stats', async (req, res) => {
+    try {
+        // Estatísticas principais
+        const mainStats = await query(`
+            SELECT 
+                (SELECT COUNT(*) FROM users) as users,
+                (SELECT COUNT(*) FROM teams) as teams,
+                (SELECT COUNT(*) FROM devices) as devices,
+                (SELECT COUNT(*) FROM policies WHERE enabled = true) as policies,
+                (SELECT COUNT(*) FROM activities WHERE DATE(created_at) = CURRENT_DATE) as activities_today,
+                (SELECT COUNT(*) FROM devices WHERE status = 'online') as devices_online,
+                (SELECT COUNT(*) FROM devices WHERE status = 'offline') as devices_offline,
+                (SELECT COUNT(*) FROM policy_commands WHERE status IN ('pending', 'sent')) as pending_commands
+        `);
+
+        // Alertas e notificações
+        const alerts = await query(`
+            SELECT 
+                (SELECT COUNT(*) FROM devices 
+                 WHERE last_seen < NOW() - INTERVAL '7 days' OR last_seen IS NULL) as devices_offline_7days,
+                
+                (SELECT COUNT(*) FROM devices d
+                 LEFT JOIN activities a ON d.device_id = a.device_id 
+                 WHERE a.created_at IS NULL OR a.created_at < NOW() - INTERVAL '24 hours') as devices_no_activity_24h,
+                
+                (SELECT COUNT(*) FROM policy_executions 
+                 WHERE status = 'failed' 
+                 AND executed_at > NOW() - INTERVAL '24 hours') as failed_policies_24h,
+                
+                (SELECT COUNT(*) FROM devices 
+                 WHERE device_info->>'needs_update' = 'true') as devices_need_update,
+                
+                (SELECT COUNT(*) FROM devices 
+                 WHERE (device_info->>'disk_free_gb')::int < 10) as low_disk_space,
+                
+                (SELECT COUNT(*) FROM users 
+                 WHERE last_login < NOW() - INTERVAL '30 days' OR last_login IS NULL) as inactive_users
+        `);
+
+        const stats = mainStats.rows[0];
+        const alertsData = alerts.rows[0];
+
+        res.json({
+            success: true,
+            stats: {
+                users: parseInt(stats.users) || 0,
+                teams: parseInt(stats.teams) || 0,
+                devices: parseInt(stats.devices) || 0,
+                policies: parseInt(stats.policies) || 0,
+                activities_today: parseInt(stats.activities_today) || 0,
+                devices_online: parseInt(stats.devices_online) || 0,
+                devices_offline: parseInt(stats.devices_offline) || 0,
+                pending_commands: parseInt(stats.pending_commands) || 0
+            },
+            alerts: {
+                devices_offline_7days: parseInt(alertsData.devices_offline_7days) || 0,
+                devices_no_activity_24h: parseInt(alertsData.devices_no_activity_24h) || 0,
+                failed_policies_24h: parseInt(alertsData.failed_policies_24h) || 0,
+                devices_need_update: parseInt(alertsData.devices_need_update) || 0,
+                low_disk_space: parseInt(alertsData.low_disk_space) || 0,
+                inactive_users: parseInt(alertsData.inactive_users) || 0
+            }
+        });
+
+    } catch (error) {
+        console.error('Erro ao obter estatísticas do dashboard:', error);
+        res.status(500).json({ 
+            success: false, 
+            error: 'Erro ao obter estatísticas do dashboard',
+            details: error.message 
+        });
+    }
+});
+
 module.exports = router;