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

package.json

@@ -6,6 +6,7 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
+    "start": "serve dist -l ${PORT:-3000}",
     "preview": "vite preview",
     "test": "vitest",
     "test:ui": "vitest --ui",
@@ -18,7 +19,8 @@
     "lucide-react": "^0.563.0",
     "@google/genai": "^1.38.0",
     "jspdf": "2.5.1",
-    "pdf-lib": "^1.17.1"
+    "pdf-lib": "^1.17.1",
+    "serve": "^14.2.4"
   },
   "devDependencies": {
     "@types/node": "^22.14.0",