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/app/(main)/settings/appearance/appearance-settings-client.tsx

@@ -63,12 +63,18 @@ export function AppearanceSettingsClient({
   }
 
   const handleFontFamilyChange = async (value: string) => {
-    const font = value === 'system' ? 'system' : 'inter'
+    const font = value === 'system' ? 'system'
+      : value === 'playfair' ? 'playfair'
+      : value === 'jetbrains' ? 'jetbrains'
+      : 'inter'
     setFontFamily(font)
     localStorage.setItem('font-family', font)
     const root = document.documentElement
-    font === 'system' ? root.classList.add('font-system') : root.classList.remove('font-system')
-    await updateAISettings({ fontFamily: font })
+    root.classList.remove('font-system', 'font-playfair', 'font-jetbrains')
+    if (font === 'system') root.classList.add('font-system')
+    if (font === 'playfair') root.classList.add('font-playfair')
+    if (font === 'jetbrains') root.classList.add('font-jetbrains')
+    await updateAISettings({ fontFamily: font as 'inter' | 'playfair' | 'jetbrains' | 'system' })
     toast.success(t('settings.settingsSaved') || 'Saved')
   }
 
@@ -192,7 +198,9 @@ export function AppearanceSettingsClient({
           description={t('appearance.fontFamilyDescription') || "Choisissez la police de l'application"}
           value={fontFamily}
           options={[
-            { value: 'inter', label: 'Inter' },
+            { value: 'inter', label: 'Inter (défaut)' },
+            { value: 'playfair', label: 'Playfair Display' },
+            { value: 'jetbrains', label: 'JetBrains Mono' },
             { value: 'system', label: t('appearance.fontSystem') || 'Système' },
           ]}
           onChange={handleFontFamilyChange}