fix: respect disabled flag for storage device alerts

Storage devices with alerts disabled in the Thresholds tab were still
triggering alerts. Added proper checking of the disabled override flag
in CheckStorage() to match the behavior of guest alerts.

internal/alerts/alerts.go

@@ -533,9 +533,27 @@ func (m *Manager) CheckStorage(storage models.Storage) {
 		m.mu.RUnlock()
 		return
 	}
+	
+	// Check if there's an override for this storage device
+	override, hasOverride := m.config.Overrides[storage.ID]
 	threshold := m.config.StorageDefault
 	m.mu.RUnlock()
 
+	// If alerts are disabled for this storage device, clear any existing alerts and return
+	if hasOverride && override.Disabled {
+		m.mu.Lock()
+		alertID := fmt.Sprintf("%s-usage", storage.ID)
+		if _, exists := m.activeAlerts[alertID]; exists {
+			delete(m.activeAlerts, alertID)
+			log.Info().
+				Str("alertID", alertID).
+				Str("storage", storage.Name).
+				Msg("Cleared alert - storage has alerts disabled")
+		}
+		m.mu.Unlock()
+		return
+	}
+
 	m.checkMetric(storage.ID, storage.Name, storage.Node, storage.Instance, "Storage", "usage", storage.Usage, &threshold)
 }