feat: add production deployment config

- Add docker-compose.prod.yml and Caddyfile for Caddy reverse proxy
- Add production stages to frontend Dockerfile (nginx for static files)
- Fix monorepo package exports for production builds (dist/src paths)
- Add CORS_ORIGIN env var for cross-origin config
- Add Better Auth baseURL, cookie domain, and trusted origins from env
- Use VITE_API_URL for API calls in auth-client and play route
- Add credentials: include for cross-origin fetch requests
- Remove unused users table from schema

apps/web/nginx.conf

@@ -0,0 +1,9 @@
+server {
+    listen 80;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+}