perf: Phase 1+2+3 — Turbopack, Prisma select, RSC page, CSS masonry + dnd-kit

- Turbopack activé (dev: next dev --turbopack)
- NOTE_LIST_SELECT: exclut embedding (~6KB/note) des requêtes de liste
- getAllNotes/getNotes/getArchivedNotes/getNotesWithReminders optimisés
- searchNotes: filtrage DB-side au lieu de full-scan JS en mémoire
- getAllNotes: requêtes ownNotes + sharedNotes parallélisées avec Promise.all
- syncLabels: upsert en transaction () vs N boucles séquentielles
- app/(main)/page.tsx converti en Server Component (RSC)
- HomeClient: composant client hydraté avec données pré-chargées
- NoteEditor/BatchOrganizationDialog/AutoLabelSuggestionDialog: lazy-loaded avec dynamic()
- MasonryGrid: remplace Muuri par CSS grid auto-fill + @dnd-kit/sortable
- 13 packages supprimés: muuri, web-animations-js, react-masonry-css, react-grid-layout
- next.config.ts nettoyé: suppression webpack override, activation image optimization

keep-notes/next.config.ts

@@ -11,30 +11,15 @@ const nextConfig: NextConfig = {
   // Enable standalone output for Docker
   output: 'standalone',
 
-  // Empty turbopack config to silence Turbopack/webpack conflict warning in Next.js 16
-  turbopack: {},
-
-  // Webpack config (needed for PWA plugin)
-  webpack: (config, { isServer }) => {
-    // Fixes npm packages that depend on `fs` module
-    if (!isServer) {
-      config.resolve.fallback = {
-        ...config.resolve.fallback,
-        fs: false,
-      };
-    }
-    return config;
-  },
-
   // Optimize for production
   reactStrictMode: true,
 
-  // Image optimization
+  // Image optimization (enabled for better performance)
   images: {
-    unoptimized: true, // Required for standalone
+    formats: ['image/avif', 'image/webp'],
   },
 
-  // Hide the "compiling" indicator as requested by the user
+  // Hide the "compiling" indicator
   devIndicators: false,
 };