feat: reminder button in list/tabs view, notifications show reminders, trash count live update

- Add reminder action to NoteActions (masonry view) and NoteMetaSidebar (tabs view)
- NotificationPanel now fetches and displays upcoming/overdue reminders alongside share requests
- Badge count includes overdue reminders; overdue items show mark-as-done toggle
- Sidebar trash count refreshes on NoteRefreshContext trigger (no more manual refresh)
- Add "Clear completed" button on reminders page with clearCompletedReminders action
- Add i18n keys for new features (en/fr)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/locales/en.json

@@ -740,7 +740,9 @@
     "markDone": "Mark as done",
     "markUndone": "Mark as undone",
     "todayAt": "Today at {time}",
-    "tomorrowAt": "Tomorrow at {time}"
+    "tomorrowAt": "Tomorrow at {time}",
+    "clearCompleted": "Clear completed",
+    "viewAll": "View all reminders"
   },
   "notebook": {
     "create": "Create Notebook",