feat: initialize project with Symfony, React, and Tailwind CSS setup

- Add package.json with development and production dependencies
- Create postcss.config.js for Tailwind CSS integration
- Implement AdminController for handling admin routes
- Add admin index template with React root element
- Create base template for consistent layout
- Configure TypeScript with tsconfig.json
- Set up Webpack configuration for asset management

tsconfig.json

@@ -0,0 +1,18 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "jsx": "react-jsx",
+    "strict": true,
+    "esModuleInterop": true,
+    "allowSyntheticDefaultImports": true,
+    "skipLibCheck": true,
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["assets/admin/*"]
+    }
+  },
+  "include": ["assets/admin/**/*"],
+  "exclude": ["node_modules", "public"]
+}