feat: add production configuration with environment variables

- Add .env file for production deployment with reverse proxy
- Add docker-compose.prod.yml for production profile
- Add docker-compose.override.yml for local development
- Update docker-compose.yml with all configurable variables
- Update frontend to use VITE_* environment variables
- Update backend to support CORS_ORIGINS and WEBHOOK_BASE_URL
- Add vite.config.ts allowedHosts for reverse proxy
- Add documentation for docker-compose and reverse proxy setup

All URLs are now configurable via environment variables:
- VITE_API_URL: Backend API endpoint
- VITE_WEBHOOK_BASE_URL: Webhook base URL
- VITE_INSTALL_SCRIPT_URL: Install script URL
- VITE_APP_URL: Frontend URL
- CORS_ORIGINS: Allowed CORS origins
- WEBHOOK_BASE_URL: Backend webhook base URL

docker-compose.prod.yml

@@ -0,0 +1,31 @@
+# Docker Compose - Production Configuration
+# Usage with reverse proxy:
+#   docker compose -f docker-compose.yml -f docker-compose.prod.yml up -d
+#
+# Required: Create a .env file with production values before running
+
+services:
+  frontend:
+    # In production, don't mount source volumes (use built image)
+    volumes:
+      - node_modules:/app/node_modules
+    
+    environment:
+      # Production API URLs - these must be set in .env file
+      - VITE_API_URL=${VITE_API_URL}
+      - VITE_WEBHOOK_BASE_URL=${VITE_WEBHOOK_BASE_URL}
+      - VITE_INSTALL_SCRIPT_URL=${VITE_INSTALL_SCRIPT_URL}
+      - VITE_APP_URL=${VITE_APP_URL}
+      - NODE_ENV=production
+
+  fake-backend:
+    environment:
+      # Production CORS - restrict to frontend domain
+      - CORS_ORIGINS=${CORS_ORIGINS}
+      
+      # Production webhook URL
+      - WEBHOOK_BASE_URL=${WEBHOOK_BASE_URL}
+      
+      # Production settings
+      - NODE_ENV=production
+      - DELAY_MS=${DELAY_MS:-1500}