improve update notifications and add apt-listchanges channel

- add an apt-listchanges notification event that surfaces package-maintainer NEWS forwarded through the PVE mail queue, with its own template, emoji and per-locale label
- emit a single post_install_update event when a tool exposes a newer version, and persist per-tool notified versions on disk so a Monitor restart no longer re-fires the same update announcement
- force AI enrichment to formatting-only on availability notices (update_available / pve_update / proxmenux_update / post_install_update / apt_listchanges / lxc_updates_available / secure_gateway_update_available / nvidia_driver_update_available / coral_driver_update_available / app_update_available / docker_stack_update_available / update_summary) so translations never turn factual inventories into advice
- add the apt_listchanges channel label to Monitor UI strings across the eight locales

AppImage/messages/de/common.json

@@ -1775,6 +1775,7 @@
         "service_fail_batch": "Mehrere Dienstausfälle",
         "cron_output": "Cron-Job-Ausgabe",
         "system_mail": "Smartd / Systemmail",
+        "apt_listchanges": "Pakethinweise von apt-listchanges",
         "webhook_test": "Webhook-Test",
         "update_available": "Verfügbare Updates (Legacy)",
         "unknown_persistent": "Scheck nicht verfügbar",

AppImage/messages/en/common.json

@@ -1774,6 +1774,7 @@
         "service_fail_batch": "Multiple service failures",
         "cron_output": "Cron job output",
         "system_mail": "Smartd / system mail",
+        "apt_listchanges": "apt-listchanges package notices",
         "webhook_test": "Webhook test",
         "update_available": "Updates available (legacy)",
         "unknown_persistent": "Check unavailable",

AppImage/messages/es/common.json

@@ -1775,6 +1775,7 @@
         "service_fail_batch": "Múltiples fallas de servicio",
         "cron_output": "Salida del trabajo cron",
         "system_mail": "Smartd / correo del sistema",
+        "apt_listchanges": "Avisos de paquetes de apt-listchanges",
         "webhook_test": "prueba de webhook",
         "update_available": "Actualizaciones disponibles (heredadas)",
         "unknown_persistent": "Verificar no disponible",

AppImage/messages/fr/common.json

@@ -1775,6 +1775,7 @@
         "service_fail_batch": "Plusieurs échecs de service",
         "cron_output": "Sortie de la tâche Cron",
         "system_mail": "Smartd / messagerie système",
+        "apt_listchanges": "Avis de paquets apt-listchanges",
         "webhook_test": "Test de webhook",
         "update_available": "Mises à jour disponibles (héritées)",
         "unknown_persistent": "Chèque indisponible",

AppImage/messages/it/common.json

@@ -1775,6 +1775,7 @@
         "service_fail_batch": "Diversi errori di servizio",
         "cron_output": "Output del lavoro Cron",
         "system_mail": "Smartd/posta di sistema",
+        "apt_listchanges": "Avvisi sui pacchetti apt-listchanges",
         "webhook_test": "Prova del webhook",
         "update_available": "Aggiornamenti disponibili (legacy)",
         "unknown_persistent": "Controlla non disponibile",

AppImage/messages/pt/common.json

@@ -1775,6 +1775,7 @@
         "service_fail_batch": "Várias falhas de serviço",
         "cron_output": "Saída do cron job",
         "system_mail": "Smartd / correio do sistema",
+        "apt_listchanges": "Avisos de pacotes do apt-listchanges",
         "webhook_test": "Teste de webhook",
         "update_available": "Atualizações disponíveis (legado)",
         "unknown_persistent": "Verifique indisponível",

AppImage/messages/sk/common.json

@@ -1774,6 +1774,7 @@
         "service_fail_batch": "Zlyhanie viacerých služieb",
         "cron_output": "Výstup úlohy cron",
         "system_mail": "Správy Smartd a systému",
+        "apt_listchanges": "Oznámenia o balíkoch apt-listchanges",
         "webhook_test": "Test webhooku",
         "update_available": "Dostupné aktualizácie (starší typ)",
         "unknown_persistent": "Kontrola nie je dostupná",

AppImage/messages/sv/common.json

@@ -1775,6 +1775,7 @@
         "service_fail_batch": "Flera tjänstefel",
         "cron_output": "Cron-jobbutdata",
         "system_mail": "Smartd / systemmail",
+        "apt_listchanges": "Paketmeddelanden från apt-listchanges",
         "webhook_test": "Webhook test",
         "update_available": "Uppdateringar tillgängliga (legacy)",
         "unknown_persistent": "Kontrollera inte tillgänglig",