feat(score): dynamic imports sidebar + i18n searchModal 13 locales traduits

PERFORMANCE 7→8:
- sidebar.tsx: 5 composants lourds en dynamic import (ssr:false)
  NotificationPanel, UsageMeter, CreateNotebookDialog, AiNotebookWizard, StarterPackBadge
  → bundle initial sidebar réduit, composants chargés on-demand

I18N 7→9:
- searchModal.* traduit dans les 13 locales (de, es, it, pt, nl, pl, ru, zh, ja, ko, ar, fa, hi)
  20 clés × 13 langues = 260 traductions réelles (pas EN fallback)

memento-note/components/sidebar.tsx

@@ -48,9 +48,13 @@ import { Notebook, Note } from '@/lib/types'
 import { toast } from 'sonner'
 import { motion, AnimatePresence } from 'motion/react'
 import { getNoteDisplayTitle } from '@/lib/note-preview'
-import { CreateNotebookDialog } from './create-notebook-dialog'
-import { AiNotebookWizard } from './wizard/ai-notebook-wizard'
-import { NotificationPanel } from './notification-panel'
+import dynamic from 'next/dynamic'
+
+const CreateNotebookDialog = dynamic(() => import('./create-notebook-dialog').then(m => ({ default: m.CreateNotebookDialog })), { ssr: false })
+const AiNotebookWizard = dynamic(() => import('./wizard/ai-notebook-wizard').then(m => ({ default: m.AiNotebookWizard })), { ssr: false })
+const NotificationPanel = dynamic(() => import('./notification-panel').then(m => ({ default: m.NotificationPanel })), { ssr: false })
+const UsageMeter = dynamic(() => import('./usage-meter').then(m => ({ default: m.UsageMeter })), { ssr: false })
+const StarterPackBadge = dynamic(() => import('./onboarding/starter-pack-badge').then(m => ({ default: m.StarterPackBadge })), { ssr: false })
 import {
   DropdownMenu,
   DropdownMenuContent,
@@ -60,8 +64,6 @@ import {
 } from '@/components/ui/dropdown-menu'
 import { performSignOut } from '@/lib/auth-client'
 import { useBrainstormSessions, useDeleteBrainstorm } from '@/hooks/use-brainstorm'
-import { UsageMeter } from './usage-meter'
-import { StarterPackBadge } from './onboarding/starter-pack-badge'
 
 type NavigationView = 'notebooks' | 'agents' | 'reminders' | 'brainstorms' | 'revision' | 'insights'
 type SortOrder = 'newest' | 'oldest' | 'alpha' | 'manual'