Fix Koyeb deployment configuration

- Update build command to use pnpm instead of npm
- Fix frontend build process in Koyeb config
- Update API URL configuration for production
- Fix database initialization in Dockerfile
- Ensure proper static file serving for SPA

Dockerfile

@@ -33,4 +33,4 @@ ENV PORT=8000
 EXPOSE 8000
 
 # 初始化数据库并启动应用
-CMD ["sh", "-c", "pnpm run db:init && pnpm start"]
+CMD ["sh", "-c", "node server/scripts/initDatabase.cjs && node server/index.cjs"]