feat: RTL/i18n, AI translate+undo, no-refresh saves, settings perf

- RTL: force dir=rtl on LabelFilter, NotesViewToggle, LabelManagementDialog
- i18n: add missing keys (notifications, privacy, edit/preview, AI translate/undo)
- Settings pages: convert to Server Components (general, appearance) + loading skeleton
- AI menu: add Translate option (10 languages) + Undo AI button in toolbar
- Fix: saveInline uses REST API instead of Server Action → eliminates all implicit refreshes in list mode
- Fix: NotesTabsView notes sync effect preserves selected note on content changes
- Fix: auto-tag suggestions now filter already-assigned labels
- Fix: color change in card view uses local state (no refresh)
- Fix: nav links use <Link> for prefetching (Settings, Admin)
- Fix: suppress duplicate label suggestions already on note
- Route: add /api/ai/translate endpoint

keep-notes/components/note-editor.tsx

@@ -142,10 +142,11 @@ export function NoteEditor({ note, readOnly = false, onClose }: NoteEditorProps)
   }
 
   // Filtrer les suggestions pour ne pas afficher celles rejetées par l'utilisateur
-  // (On garde celles déjà ajoutées pour les afficher en mode "validé")
+  // ni celles déjà présentes sur la note
+  const existingLabelsLower = (note.labels || []).map((l) => l.toLowerCase())
   const filteredSuggestions = suggestions.filter(s => {
     if (!s || !s.tag) return false
-    return !dismissedTags.includes(s.tag)
+    return !dismissedTags.includes(s.tag) && !existingLabelsLower.includes(s.tag.toLowerCase())
   })
 
   const handleImageUpload = async (e: React.ChangeEvent<HTMLInputElement>) => {