feat: Add Railway deployment configuration

- Add serve as production server for static files
- Add start script for production deployment
- Create railway.toml with deployment settings
- Create .env.example for required environment variables
- Fix index.html to use Vite bundling instead of ESM imports

https://claude.ai/code/session_01DBAyjuKW8Qtzixc64qn9KP

railway.toml

@@ -0,0 +1,9 @@
+[build]
+builder = "nixpacks"
+
+[deploy]
+startCommand = "npm start"
+healthcheckPath = "/"
+healthcheckTimeout = 100
+restartPolicyType = "on_failure"
+restartPolicyMaxRetries = 3