feat: refactor and optimize frontend with Next.js App Router, TypeScript, and Tailwind CSS

- Complete refactoring of old frontend into Next.js App Router workspace
- Redesigned sidebar collapsing animation with absolute toggle positioning
- Resolved visual canvas bleed transitions between light/dark themes
- Added custom dark theme variant for toggle switch buttons
- Implemented full localization across Indonesian, English, Spanish, Japanese, and Chinese
- Synchronized HTML document themes to apply dark mode styles to portals/overlays

frontend-next/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "frontend-next",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build && node copy-build.js",
+    "start": "next start",
+    "lint": "eslint"
+  },
+  "dependencies": {
+    "clsx": "^2.1.1",
+    "framer-motion": "^12.40.0",
+    "lucide-react": "^1.17.0",
+    "next": "16.2.6",
+    "react": "19.2.4",
+    "react-dom": "19.2.4",
+    "tailwind-merge": "^3.6.0"
+  },
+  "devDependencies": {
+    "@tailwindcss/postcss": "^4",
+    "@types/node": "^20",
+    "@types/react": "^19",
+    "@types/react-dom": "^19",
+    "eslint": "^9",
+    "eslint-config-next": "16.2.6",
+    "tailwindcss": "^4",
+    "typescript": "^5"
+  }
+}