feat: auto-save 2s + indicateur save + reminders inline actions (compléter/snooze)

- Auto-save debounce 2s dans note-editor-context
- lastSavedAt state + setIsDirty(false) dans handleSave
- Indicateur toolbar: ✓ sauvegardé / ● non enregistré avec timer relatif
- Reminders sidebar: bouton ✓ compléter + bouton +1h snooze (hover inline)
- i18n: clés reminders.markDone/snooze1h + notes.savedJustNow/unsaved (15 locales)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

memento-note/components/note-editor/note-editor-context.tsx

@@ -81,6 +81,7 @@ export function NoteEditorProvider({ note, readOnly = false, fullPage = false, o
   const [color, setColor] = useState(note.color)
   const [size, setSize] = useState<NoteSize>(note.size || 'small')
   const [isSaving, setIsSaving] = useState(false)
+  const [lastSavedAt, setLastSavedAt] = useState<Date | null>(null)
   const [removedImageUrls, setRemovedImageUrls] = useState<string[]>([])
   const [isMarkdown, setIsMarkdown] = useState(note.type === 'markdown')
   const [showMarkdownPreview, setShowMarkdownPreview] = useState(note.type === 'markdown')
@@ -691,6 +692,8 @@ export function NoteEditorProvider({ note, readOnly = false, fullPage = false, o
       queryClient.invalidateQueries({ queryKey: queryKeys.note(note.id) })
       queryClient.invalidateQueries({ queryKey: queryKeys.notes(note.notebookId) })
       emitNoteChange({ type: 'updated', note: result })
+      setIsDirty(false)
+      setLastSavedAt(new Date())
       toast.success(t('notes.saved') || 'Note sauvegardée !')
     } catch (error) {
       console.error('[SAVE] updateNote failed:', error)
@@ -816,6 +819,7 @@ export function NoteEditorProvider({ note, readOnly = false, fullPage = false, o
       queryClient.invalidateQueries({ queryKey: queryKeys.notes(note.notebookId) })
       emitNoteChange({ type: 'updated', note: result })
       setIsDirty(false)
+      setLastSavedAt(new Date())
       toast.success(t('notes.saved') || 'Saved')
     } catch (error) {
       console.error('[SAVE] updateNote failed:', error)
@@ -830,6 +834,23 @@ export function NoteEditorProvider({ note, readOnly = false, fullPage = false, o
   const handleSaveRef = useRef(handleSave)
   handleSaveRef.current = handleSave
 
+  // Auto-save : 2s après le dernier changement si isDirty
+  const autoSaveTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
+  useEffect(() => {
+    if (!isDirty || isSaving || readOnly) return
+    if (autoSaveTimerRef.current) clearTimeout(autoSaveTimerRef.current)
+    autoSaveTimerRef.current = setTimeout(() => {
+      if (fullPage) {
+        void handleSaveInPlaceRef.current()
+      } else {
+        void handleSaveRef.current()
+      }
+    }, 2000)
+    return () => {
+      if (autoSaveTimerRef.current) clearTimeout(autoSaveTimerRef.current)
+    }
+  }, [isDirty, isSaving, readOnly, fullPage])
+
   useEffect(() => {
     if (!fullPage) return
     const handler = (e: KeyboardEvent) => {
@@ -870,6 +891,7 @@ export function NoteEditorProvider({ note, readOnly = false, fullPage = false, o
     removedImageUrls,
     isSaving,
     isDirty,
+    lastSavedAt,
     isProcessingAI,
     aiOpen,
     infoOpen,
@@ -894,7 +916,7 @@ export function NoteEditorProvider({ note, readOnly = false, fullPage = false, o
     quotaExceededFeature,
   }), [
     title, content, checkItems, labels, images, links, newLabel, color, size,
-    showMarkdownPreview, removedImageUrls, isSaving, isDirty, isProcessingAI, aiOpen, infoOpen,
+    showMarkdownPreview, removedImageUrls, isSaving, isDirty, lastSavedAt, isProcessingAI, aiOpen, infoOpen,
     isGeneratingTitles, titleSuggestions, dismissedTitleSuggestions, isReformulating,
     reformulationModal, previousContentForCopilot, showReminderDialog, currentReminder,
     showLinkDialog, linkUrl, comparisonNotes, fusionNotes, dismissedTags, filteredSuggestions,