SalesforceCommerceCloud/pwa-kit ? reverse-engineered prompt

Build me a modern storefront starter for Salesforce Commerce that a team could use to launch a shopping site fast.

I want it to be a React based progressive web app, with a polished retail demo storefront, product browsing, search, cart, and a good mobile experience. It should be easy to set up with a new sandbox, run locally right away, and then deploy to Managed Runtime when we are ready. Please make it feel production ready, with sensible defaults, routing, localization support, and clear places to connect to Salesforce Commerce APIs.

If there are any current best practices or docs I should follow, look them up online and use them. Keep the code organized so it is easy to customize for a real brand, and make sure the app works well as a fast, installable PWA.