feat: initial import — ClickerZ formation project (Express + React/Vite)

Backend/.env.sample

@@ -0,0 +1,15 @@
+# .env.sample - Sample Environment Variables
+
+# Application Configuration
+APP_PORT=3310
+APP_SECRET=YOUR_APP_SECRET_KEY
+
+# Database Configuration
+DB_HOST=localhost
+DB_PORT=3306
+DB_USER=YOUR_DATABASE_USERNAME
+DB_PASSWORD=YOUR_DATABASE_PASSWORD
+DB_NAME=YOUR_DATABASE_NAME
+
+# Frontend URL (for CORS configuration)
+FRONTEND_URL=http://localhost:3000