feat: Initialize core frontend application, editor layout, and integrate UI components including alert dialogs and toasts.

frontend/package.json

@@ -11,6 +11,7 @@
   },
   "dependencies": {
     "@monaco-editor/react": "^4.7.0",
+    "@radix-ui/react-alert-dialog": "^1.1.15",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-label": "^2.1.8",
     "@radix-ui/react-scroll-area": "^1.2.10",
@@ -21,8 +22,10 @@
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "lucide-react": "^0.575.0",
+    "next-themes": "^0.4.6",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
+    "sonner": "^2.0.7",
     "tailwind-merge": "^3.5.0",
     "tailwindcss": "^3.4.19",
     "tailwindcss-animate": "^1.0.7"