fix(chart): improve error handling and color variety

- Add quotaExceeded flag to response for better error UX
- Show dedicated quota exceeded state with upgrade button
- Improve AI prompt to better detect data patterns
- Add chart type-specific colors (blue, indigo, emerald, violet, etc.)
- Replace generic primary/10 colors with varied accent colors

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

memento-note/locales/fr.json

@@ -2664,5 +2664,28 @@
     "emptyState": "Aucune version disponible",
     "selectVersion": "Sélectionnez une version pour prévisualiser son contenu",
     "currentVersion": "actuelle"
+  },
+  "graphView": {
+    "title": "Vue en graphe",
+    "notesCount": "{count} notes",
+    "connectionsCount": "{count} liens",
+    "globalView": "Vue globale",
+    "searchPlaceholder": "Filtrer...",
+    "noNotesFound": "Aucune note trouvée",
+    "notebooks": "Carnets",
+    "resetFilter": "Réinitialiser",
+    "relationshipTypes": "Types de liaisons",
+    "connections": "{count} liaison",
+    "connectionsPlural": "{count} liaisons",
+    "preview": {
+      "openNote": "Ouvrir la note",
+      "emptyNote": "Note vide",
+      "tags": "Tags",
+      "noTags": "Aucun tag",
+      "words": "{count} mots",
+      "chars": "{count} ch.",
+      "created": "Créée le",
+      "updated": "Mise à jour le"
+    }
   }
 }