feat: demo page realisation

package.json

@@ -25,10 +25,13 @@
     "axios": "^1.9.0",
     "easymde": "^2.20.0",
     "i18n-iso-countries": "^7.14.0",
+    "lodash": "^4.18.1",
     "lucide-react": "^0.511.0",
     "mobx": "^6.13.7",
     "mobx-react-lite": "^4.1.0",
     "ol": "^10.5.0",
+    "overlayscrollbars": "^2.15.1",
+    "overlayscrollbars-react": "^0.5.6",
     "path": "^0.12.7",
     "pixi.js": "^8.10.1",
     "react": "^19.1.0",
@@ -39,6 +42,7 @@
     "react-router-dom": "^7.6.1",
     "react-simplemde-editor": "^5.2.0",
     "react-toastify": "^11.0.5",
+    "react-transition-group": "^4.4.5",
     "rehype-raw": "^7.0.0",
     "tailwindcss": "^4.1.8",
     "three": "^0.177.0",
@@ -47,6 +51,7 @@
   "devDependencies": {
     "@eslint/js": "^9.25.0",
     "@tailwindcss/typography": "^0.5.16",
+    "@types/lodash": "^4.17.24",
     "@types/node": "^22.15.24",
     "@types/react": "^19.1.2",
     "@types/react-dom": "^19.1.2",