feat: migrate to Next.js for Mini App and enhance project structure

- Replaced the previous webapp with a new Mini App built using Next.js, improving performance and maintainability.
- Updated the `.gitignore` to exclude Next.js build artifacts and node modules.
- Revised documentation in `AGENTS.md`, `README.md`, and `architecture.md` to reflect the new Mini App structure and technology stack.
- Enhanced Dockerfile to support the new build process for the Next.js application.
- Updated CI workflow to build and test the Next.js application.
- Added new configuration options for the Mini App, including `MINI_APP_SHORT_NAME` for improved deep linking.
- Refactored frontend testing setup to accommodate the new structure and testing framework.
- Removed legacy webapp files and dependencies to streamline the project.

webapp-next/package.json

@@ -0,0 +1,45 @@
+{
+  "name": "webapp-next",
+  "version": "0.1.0",
+  "private": true,
+  "engines": {
+    "node": ">=20.9.0"
+  },
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build",
+    "start": "next start",
+    "lint": "eslint src/",
+    "test": "vitest run",
+    "test:watch": "vitest"
+  },
+  "dependencies": {
+    "@telegram-apps/sdk-react": "^3.3.9",
+    "class-variance-authority": "^0.7.1",
+    "clsx": "^2.1.1",
+    "lucide-react": "^0.576.0",
+    "next": "16.1.6",
+    "radix-ui": "^1.4.3",
+    "react": "19.2.3",
+    "react-dom": "19.2.3",
+    "tailwind-merge": "^3.5.0",
+    "zustand": "^5.0.11"
+  },
+  "devDependencies": {
+    "@tailwindcss/postcss": "^4",
+    "@testing-library/jest-dom": "^6.6.3",
+    "@testing-library/react": "^16.3.0",
+    "@types/node": "^20",
+    "@types/react": "^19",
+    "@types/react-dom": "^19",
+    "@vitejs/plugin-react": "^4.5.2",
+    "eslint": "^9",
+    "eslint-config-next": "16.1.6",
+    "jsdom": "^26.0.0",
+    "shadcn": "^3.8.5",
+    "tailwindcss": "^4",
+    "tw-animate-css": "^1.4.0",
+    "typescript": "^5",
+    "vitest": "^3.2.4"
+  }
+}