Bill Payment system offline

Executive Summary

Grace Super Shop Smart POS & Billing System is an offline-first retail checkout and inventory management application designed for grocery stores and super shops. Built with React, Vite, and Supabase, it provides 0ms checkout latency with full hard-refresh cart persistence even when disconnected from the internet. Key features include hardware laser barcode scanner integration, manual loose-item billing, authentic 58mm/80mm thermal receipt printing (complete with VAT breakdown, discounts, and return barcodes), multi-channel payments (Cash with denomination change calculator, bKash, Nagad, Rocket, Visa/Mastercard), brand-based inventory filtering, bulk discount engines, and real-time cloud synchronization with Supabase.