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/theme-initializer.tsx

@@ -47,11 +47,10 @@ export function ThemeInitializer({ theme, fontSize, fontFamily }: ThemeInitializ
     const localFontFamily = localStorage.getItem('font-family')
     const effectiveFontFamily = localFontFamily || fontFamily || 'inter'
     const root = document.documentElement
-    if (effectiveFontFamily === 'system') {
-      root.classList.add('font-system')
-    } else {
-      root.classList.remove('font-system')
-    }
+    root.classList.remove('font-system', 'font-playfair', 'font-jetbrains')
+    if (effectiveFontFamily === 'system') root.classList.add('font-system')
+    if (effectiveFontFamily === 'playfair') root.classList.add('font-playfair')
+    if (effectiveFontFamily === 'jetbrains') root.classList.add('font-jetbrains')
     if (!localFontFamily && fontFamily) {
       localStorage.setItem('font-family', fontFamily)
     }