feat(nextcloud-status): Dashboard-Kachel, Anleitung und Changelog

- Kachel mit Zählern und roten/gelben Clouds, nur mit Modulzugriff sichtbar (geteilte Widget-Typen, Modulzuordnung, Katalog)
- Anleitung für Anwender und Administratoren, Eintrag im Changelog

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

apps/web/src/messages/en.json

@@ -521,6 +521,10 @@
     "emptyState": {
       "title": "Your dashboard is still empty",
       "body": "Build your start page from tiles. For example:"
+    },
+    "nextcloudStatus": {
+      "name": "Nextcloud status",
+      "description": "Traffic-light overview of your Nextcloud clouds"
     }
   },
   "admin": {
@@ -1895,6 +1899,14 @@
       "saveError": "The cloud could not be saved.",
       "deleteError": "The cloud could not be removed.",
       "close": "Close dialog"
+    },
+    "widget": {
+      "loading": "Loading status …",
+      "loadError": "Status could not be loaded",
+      "empty": "No cloud added yet",
+      "allGood": "All clouds are up to date",
+      "countsLabel": "Number of clouds per traffic-light color",
+      "open": "Open Nextcloud status"
     }
   }
 }