chore: remove unused files and update package dependencies

package.json

@@ -24,20 +24,12 @@
     "astro": "^5.4.2",
     "astro-icon": "^1.1.5",
     "framer-motion": "^12.4.7",
-    "lenis": "^1.2.3",
-    "next": "15.1.7",
-    "react": "^19.0.0",
-    "react-dom": "^19.0.0",
-    "react-icons": "^5.5.0",
-    "react-intersection-observer": "^9.15.1"
+    "lenis": "^1.2.3"
   },
   "devDependencies": {
     "@eslint/eslintrc": "^3",
     "@types/node": "^20",
-    "@types/react": "^19.0.10",
-    "@types/react-dom": "^19.0.4",
     "eslint": "^9",
-    "eslint-config-next": "15.1.7",
     "eslint-config-prettier": "^10.1.1",
     "postcss": "^8",
     "prettier": "^3.5.3",