feat: icon-only toolbar, versioning fixes, history modal, PanelRight repositioning

- Toolbar: remove text labels from all icon buttons (AI, Save, Preview, Convert)
  all buttons now icon-only with title tooltip for accessibility
- Toolbar: reposition PanelRight (info panel toggle) to far right after three-dot menu
- Versioning: decouple getNoteHistory/restoreNoteVersion from global userAISettings.noteHistory
  now checks note.historyEnabled directly — unblocks manual per-note history
- Versioning: add 'Sauvegarder cette version' button in Versions tab of info panel
  calls commitNoteHistory with visual feedback (spinner → success state)
- note-document-info-panel: import commitNoteHistory, add isSavingVersion state
- notes.ts: fix double guard that silently blocked all history operations

memento-note/components/notes-editorial-view.tsx

@@ -264,7 +264,7 @@ export function NotesEditorialView({
   }, [session?.user?.id])
 
   return (
-    <div className="mx-auto w-full max-w-3xl space-y-16">
+    <div className="mx-auto w-full max-w-3xl space-y-8">
       <AnimatePresence>
         {notes.map((note: Note, index: number) => {
           const title = getNoteDisplayTitle(note, t('notes.untitled') || 'Untitled')
@@ -277,14 +277,19 @@ export function NotesEditorialView({
               initial={{ opacity: 0, y: 20 }}
               animate={{ opacity: 1, y: 0 }}
               transition={{ delay: 0.05 * index, duration: 0.6 }}
-              className="space-y-4 group cursor-pointer relative border-b border-border/20 pb-16"
+              className="space-y-4 group cursor-pointer relative pb-8"
               onClick={() => onOpen(note)}
             >
-              {/* Date / breadcrumb + actions menu */}
-              <div className="flex items-center justify-between">
-                <div className="note-date-badge">
-                  {notebookName ? `${notebookName} — ${dateStr}` : dateStr}
-                </div>
+              {/* Date / breadcrumb */}
+              <div className="note-date-badge">
+                {notebookName ? `${notebookName} — ${dateStr}` : dateStr}
+              </div>
+
+              {/* Actions menu — absolutely positioned at top-right */}
+              <div
+                className="absolute top-0 right-0 opacity-0 group-hover:opacity-100 transition-opacity"
+                onClick={e => e.stopPropagation()}
+              >
                 <EditorialNoteMenu note={note} onOpen={onOpen} onOpenHistory={onOpenHistory} />
               </div>