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.override.yml

@@ -0,0 +1,23 @@
+# Docker Compose Override - Local Development Configuration
+# This file is automatically loaded by Docker Compose and overrides docker-compose.yml
+# Use this for local development settings without modifying the main docker-compose.yml
+#
+# Usage: docker compose up -d (automatically loads this file)
+#
+# To use production configuration, create a .env file and run:
+#   docker compose -f docker-compose.yml up -d
+
+services:
+  frontend:
+    environment:
+      # Development defaults - override these in .env file for production
+      - VITE_API_URL=http://192.168.254.79:3001
+      - VITE_WEBHOOK_BASE_URL=http://192.168.254.79:3001/webhook
+      - VITE_INSTALL_SCRIPT_URL=http://192.168.254.79:3001/install.sh
+      - VITE_APP_URL=http://192.168.254.79:5173
+
+  fake-backend:
+    environment:
+      # Development defaults
+      - CORS_ORIGINS=*
+      - WEBHOOK_BASE_URL=http://192.168.254.79:3001/webhook