fix: redesign note history disabled state with centered icon + better copy

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/locales/en.json

@@ -175,7 +175,8 @@
     "history": "History",
     "historyRestored": "Version restored",
     "historyEnabled": "History enabled",
-    "historyDisabledDesc": "History is disabled for your account.",
+    "historyDisabledTitle": "Version history",
+    "historyDisabledDesc": "Track changes to this note over time. Enable history to start recording versions.",
     "enableHistory": "Enable history",
     "historyEmpty": "No versions available",
     "historySelectVersion": "Select a version to preview its content",

memento-note/locales/fr.json

@@ -999,7 +999,8 @@
     "history": "Historique",
     "historyRestored": "Version restaurée",
     "historyEnabled": "Historique activé",
-    "historyDisabledDesc": "L'historique est désactivé pour votre compte.",
+    "historyDisabledTitle": "Historique des versions",
+    "historyDisabledDesc": "Suivez les modifications de cette note au fil du temps. Activez l'historique pour commencer à enregistrer des versions.",
     "enableHistory": "Activer l'historique",
     "historyEmpty": "Aucune version disponible",
     "historySelectVersion": "Sélectionnez une version pour prévisualiser son contenu",