Revert "Created React subproject"

This reverts commit a9775f4fa5.

frontend/package.json

@@ -1,27 +0,0 @@
-{
-  "name": "frontend",
-  "private": true,
-  "version": "0.0.0",
-  "type": "module",
-  "scripts": {
-    "dev": "vite",
-    "build": "vite build",
-    "lint": "eslint .",
-    "preview": "vite preview"
-  },
-  "dependencies": {
-    "react": "^19.0.0",
-    "react-dom": "^19.0.0"
-  },
-  "devDependencies": {
-    "@eslint/js": "^9.21.0",
-    "@types/react": "^19.0.10",
-    "@types/react-dom": "^19.0.4",
-    "@vitejs/plugin-react": "^4.3.4",
-    "eslint": "^9.21.0",
-    "eslint-plugin-react-hooks": "^5.1.0",
-    "eslint-plugin-react-refresh": "^0.4.19",
-    "globals": "^15.15.0",
-    "vite": "^6.2.0"
-  }
-}