feat(ui): panneau repliable, carnets plus lisibles et accueil plus clair

Harmonise la liste des notes et l’éditeur (titres, dates, retour),
rend la saisie rapide et les raccourcis de l’accueil utilisables
sur téléphone, et conserve le panneau latéral repliable.

memento-note/components/note-editor/note-editor-split-peek.tsx

@@ -8,9 +8,7 @@ import { useLanguage } from '@/lib/i18n'
 import { NoteEditorProvider, useNoteEditorContext } from './note-editor-context'
 import { NoteTitleBlock } from './note-title-block'
 import { NoteContentArea } from './note-content-area'
-import { formatAbsoluteDateLocalized } from '@/lib/utils/format-localized-date'
-import { fr } from 'date-fns/locale/fr'
-import { enUS } from 'date-fns/locale/en-US'
+import { dateTextDirection, formatNoteCalendarDate } from '@/lib/utils/format-localized-date'
 
 interface NoteEditorSplitPeekProps {
   note: Note
@@ -23,7 +21,7 @@ interface NoteEditorSplitPeekProps {
 function PeekEditorBody({ blockId }: { blockId?: string }) {
   const { note } = useNoteEditorContext()
   const { t, language } = useLanguage()
-  const dateLocale = language === 'fr' ? fr : enUS
+  const dateDir = dateTextDirection(language)
   const scrollRootRef = useRef<HTMLDivElement>(null)
 
   useEffect(() => {
@@ -40,10 +38,12 @@ function PeekEditorBody({ blockId }: { blockId?: string }) {
     <div ref={scrollRootRef} className="flex-1 min-h-0 overflow-y-auto">
       <div className="max-w-2xl mx-auto w-full px-6 sm:px-8 py-10 space-y-8 pb-24">
         <p
-          className="text-[10px] uppercase tracking-[.25em] font-bold text-[var(--color-concrete)]"
+          className="text-[10px] font-medium tracking-normal text-[var(--color-concrete)]"
+          dir={dateDir}
+          lang={language === 'fa' ? 'fa' : language === 'ar' ? 'ar' : undefined}
           suppressHydrationWarning
         >
-          {formatAbsoluteDateLocalized(new Date(note.contentUpdatedAt), language, 'MMM d, yyyy', dateLocale)}
+          {formatNoteCalendarDate(note.contentUpdatedAt, language)}
         </p>
         <NoteTitleBlock />
         <div className="max-w-xl mx-auto w-full">
@@ -85,7 +85,7 @@ export function NoteEditorSplitPeek({ note, blockId, onClose, onOpenFully, onBac
                 className="inline-flex items-center gap-1.5 px-2.5 py-1.5 rounded-lg text-[10px] font-bold uppercase tracking-wide text-ink dark:text-dark-ink hover:bg-black/5 dark:hover:bg-white/5 transition-colors"
               >
                 <LayoutGrid size={12} />
-                {t('notes.backToDashboard')}
+                {t('notes.backToHome')}
               </button>
             )}
             <button