fix(settings): shorten the notifications section label to one line

The notification-channels section heading and the left-nav label both
render `settings.sections.notifications.title`, whose German value
("Benachrichtigungs-Kanäle") is a long compound that wraps to two lines
in the nav rail. Shorten the displayed value to the plain plural across
all six locales (de "Benachrichtigungen"; en "Notifications"; es
"Notificaciones"; fr "Notifications"; it "Notifiche"; pl
"Powiadomienia"). Key id is unchanged; the breadcrumb on the
notification-center page keeps its own wording.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
(cherry picked from commit af437f48b09b9f99b6a80709ddacd565c10132ab)

messages/de.json

@@ -2671,7 +2671,7 @@
         "description": "Withings, moodLog und weitere verbundene Dienste."
       },
       "notifications": {
-        "title": "Benachrichtigungs-Kanäle",
+        "title": "Benachrichtigungen",
         "description": "Live-Übersicht aller konfigurierten Kanäle."
       },
       "dashboard": {

messages/en.json

@@ -2671,7 +2671,7 @@
         "description": "Withings, moodLog, and other connected services."
       },
       "notifications": {
-        "title": "Notification channels",
+        "title": "Notifications",
         "description": "Live overview of every configured channel."
       },
       "dashboard": {

messages/es.json

@@ -2671,7 +2671,7 @@
         "description": "Withings, moodLog, and other connected services."
       },
       "notifications": {
-        "title": "Canales de notificación",
+        "title": "Notificaciones",
         "description": "Live overview of every configured channel."
       },
       "dashboard": {

messages/fr.json

@@ -2671,7 +2671,7 @@
         "description": "Withings, moodLog, and other connected services."
       },
       "notifications": {
-        "title": "Canaux de notification",
+        "title": "Notifications",
         "description": "Live overview of every configured channel."
       },
       "dashboard": {

messages/it.json

@@ -2671,7 +2671,7 @@
         "description": "Withings, moodLog, and other connected services."
       },
       "notifications": {
-        "title": "Canali di notifica",
+        "title": "Notifiche",
         "description": "Live overview of every configured channel."
       },
       "dashboard": {

messages/pl.json

@@ -2671,7 +2671,7 @@
         "description": "Withings, moodLog, and other connected services."
       },
       "notifications": {
-        "title": "Kanały powiadomień",
+        "title": "Powiadomienia",
         "description": "Live overview of every configured channel."
       },
       "dashboard": {