baopd79/rental-system — reverse-engineered prompt

Build me a Vietnamese rental house management SaaS called VnRental for small landlords who manage rooms across one or more buildings.

Landlords should be able to sign up, add properties, rooms, tenants, and rental contracts, then enter monthly electricity and water meter readings. The app should calculate monthly invoices automatically, including rent, water, electricity, surcharges, shared meters, and partial month prorating when someone moves in or out. It should support generating invoices for all rooms in a property at once and clearly show which rooms were skipped because of missing readings, no active contract, or an existing invoice.

Tenants shouldn’t need an account. Each invoice should have a public share link that opens a clean printable invoice page, safe to send through Zalo or SMS. Landlords also need a dashboard showing monthly revenue, vacancy rate, and contracts expiring soon.

Use a modern web app setup with authentication, a real database, and a backend API. Keep each landlord’s data separate and secure. Look up current docs online if needed.