feat: add custom icons for Zabbix, Centreon, Nagios, PRTG, Eaton, Riello, Vertiv

UPS: Eaton (lightning bolt, #E22000), Riello (battery+, #0066B3),
     Vertiv (server rack, #0079A7)
Monitoring: Zabbix (activity line, #D40000), Centreon (bulb/hub, #0071CE),
            Nagios (magnifier, #2D72D2), PRTG (speedometer, #7AB648)

All use thematic SVG paths on 24×24 viewBox, consistent with existing
custom icons (ICON_FREE, ICON_BASTION, ICON_MAIL, etc.).
READMEs (fr/en/es) updated.

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

README.fr.md

@@ -288,6 +288,9 @@ Plusieurs logos peuvent s'afficher simultanément si plusieurs mots-clés corres
 | NAS | Synology | `synology`, `dsm` |
 | NAS | TrueNAS | `truenas`, `freenas` |
 | Onduleur (UPS) | Schneider Electric / APC | `apc`, `schneider electric`, `symmetra`, `smart-ups`, `easy ups`, `galaxy ups` |
+| Onduleur (UPS) | Eaton | `eaton`, `powerware`, `eaton ups` |
+| Onduleur (UPS) | Riello | `riello`, `riello ups` |
+| Onduleur (UPS) | Vertiv | `vertiv`, `liebert`, `avocent`, `geist` |
 | FAI français | Orange | `orange`, `sosh`, `livebox` |
 | FAI français | OVH | `ovh`, `ovhcloud`, `kimsufi`, `soyoustart` |
 | FAI français | Free | `freebox`, `free mobile`, `free telecom`, `iliad` |
@@ -321,6 +324,10 @@ Plusieurs logos peuvent s'afficher simultanément si plusieurs mots-clés corres
 | Messagerie | Serveur mail | `mail`, `smtp`, `imap`, `postfix`, `dovecot`, `mailcow`, `mailu`, `roundcube` |
 | Base de données | MariaDB | `mariadb`, `maria db` |
 | Orchestration | Kubernetes | `kubernetes`, `k8s`, `kubectl`, `k3s` |
+| Monitoring | Zabbix | `zabbix` |
+| Monitoring | Centreon | `centreon` |
+| Monitoring | Nagios | `nagios`, `nagiosxi`, `nagios xi` |
+| Monitoring | PRTG | `prtg`, `paessler` |
 | Monitoring | Prometheus | `prometheus` |
 | Monitoring | Grafana | `grafana` |
 | Monitoring | Datadog | `datadog` |