iscale-llc/agentic-react-nextjs-shadcn ? reverse-engineered prompt

Build me a polished SaaS starter app with a clean dashboard, login page, and a protected main area after sign in. I want a modern interface with a sidebar, top nav, cards, tables, forms, and a few sample pages like users, activity, analytics, settings, and a simple spreadsheet style page. Make it feel like a real product, not a demo.

Use a strong accessible design throughout, with proper labels, keyboard friendly controls, readable table states, loading and error states, and good semantic structure so it works well with automated browser tests. Include a simple auth flow, database backed data, and basic CRUD for users. Keep the code clean and ready to extend, with seed data for development and a way to run tests. If you need to check current docs for any library behavior, do that.