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/context/home-view-context.tsx

@@ -0,0 +1,36 @@
+'use client'
+
+import { createContext, useContext, useMemo, useState, type ReactNode } from 'react'
+
+export type HomeUiControls = {
+  isTabsMode: boolean
+  openNoteComposer: () => void
+}
+
+type Ctx = {
+  controls: HomeUiControls | null
+  setControls: (c: HomeUiControls | null) => void
+}
+
+const HomeViewContext = createContext<Ctx | null>(null)
+
+export function HomeViewProvider({ children }: { children: ReactNode }) {
+  const [controls, setControls] = useState<HomeUiControls | null>(null)
+  const value = useMemo(() => ({ controls, setControls }), [controls])
+
+  return <HomeViewContext.Provider value={value}>{children}</HomeViewContext.Provider>
+}
+
+/** Enregistré par la page d’accueil ; la sidebar lit `controls` */
+export function useHomeView() {
+  const ctx = useContext(HomeViewContext)
+  if (!ctx) {
+    throw new Error('useHomeView must be used within HomeViewProvider')
+  }
+  return ctx
+}
+
+/** Sidebar / shells : ne pas planter si hors provider */
+export function useHomeViewOptional(): Ctx | null {
+  return useContext(HomeViewContext)
+}