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/note-document-info-panel.tsx

@@ -11,7 +11,7 @@ import { useLanguage } from '@/lib/i18n'
 import { useNotebooks } from '@/context/notebooks-context'
 import { LabelBadge } from './label-badge'
 import { NoteHistoryModal } from './note-history-modal'
-import { enableNoteHistory } from '@/app/actions/notes'
+import { enableNoteHistory, commitNoteHistory } from '@/app/actions/notes'
 
 type Tab = 'info' | 'versions'
 
@@ -47,6 +47,8 @@ export function NoteDocumentInfoPanel({ note, content, onClose, onNoteRestored }
   const [activeTab, setActiveTab] = useState<Tab>('info')
   const [showHistory, setShowHistory] = useState(false)
   const [historyEnabled, setHistoryEnabled] = useState(note.historyEnabled ?? false)
+  const [isSavingVersion, setIsSavingVersion] = useState(false)
+  const [versionSaved, setVersionSaved] = useState(false)
   const locale = getLocale(language)
 
   const notebook = useMemo(
@@ -62,7 +64,7 @@ export function NoteDocumentInfoPanel({ note, content, onClose, onNoteRestored }
 
   return (
     <>
-      <div className="flex w-80 shrink-0 flex-col border-l border-border/40 bg-background overflow-hidden">
+      <div className="flex w-full h-full flex-col bg-background overflow-hidden">
 
         {/* Header tabs */}
         <div className="flex items-center justify-between px-5 py-4 border-b border-border/40">
@@ -199,8 +201,42 @@ export function NoteDocumentInfoPanel({ note, content, onClose, onNoteRestored }
                   </button>
                 </div>
               ) : (
-                <div className="space-y-2">
-                  <p className="text-[10px] uppercase tracking-widest text-muted-foreground mb-3">Versions sauvegardées</p>
+              <div className="space-y-3">
+                  <p className="text-[10px] uppercase tracking-widest text-muted-foreground">Versions sauvegardées</p>
+
+                  {/* Save version button */}
+                  <button
+                    disabled={isSavingVersion}
+                    className={cn(
+                      'w-full flex items-center justify-center gap-2 p-3 rounded-xl border transition-colors text-sm font-medium',
+                      versionSaved
+                        ? 'border-emerald-500/40 bg-emerald-50 dark:bg-emerald-950/30 text-emerald-700 dark:text-emerald-400'
+                        : 'border-foreground/20 bg-foreground text-background hover:opacity-80',
+                      isSavingVersion && 'opacity-50 cursor-not-allowed'
+                    )}
+                    onClick={async () => {
+                      setIsSavingVersion(true)
+                      try {
+                        await commitNoteHistory(note.id)
+                        setVersionSaved(true)
+                        setTimeout(() => setVersionSaved(false), 3000)
+                      } catch (e) {
+                        console.error(e)
+                      } finally {
+                        setIsSavingVersion(false)
+                      }
+                    }}
+                  >
+                    {isSavingVersion ? (
+                      <><span className="h-3.5 w-3.5 rounded-full border-2 border-current border-t-transparent animate-spin" />Sauvegarde…</>
+                    ) : versionSaved ? (
+                      <><span className="text-base">✓</span> Version sauvegardée !</>
+                    ) : (
+                      <><span className="text-base">⎘</span> Sauvegarder cette version</>
+                    )}
+                  </button>
+
+                  {/* View history */}
                   <button
                     className="w-full flex items-center justify-between p-3 rounded-xl border border-border hover:bg-muted transition-colors text-left"
                     onClick={() => setShowHistory(true)}