fufex3934/perdiem-management-system ? reverse-engineered prompt

Build me a multi tenant per diem management app for companies that handle employee travel requests, approvals, and payments.

I want employees to submit travel requests, managers and admins to review and approve them in steps, and finance to track the resulting payment records from pending to paid or failed. It should also include a simple dashboard, notifications for request updates and approvals, CSV exports for finance and reports, and a security audit log for important actions.

Make it a full working product with a backend API and a modern web app, with a clean admin style UI that feels good to use. Use the current best practices for a production ready app, including login, role based access, health checks, and good error handling. If you need to confirm any current docs or small implementation details, look them up online first.