Xero Invoices Dashboard Integration

I have a Replit workspace running a small Node.js app with a PostgreSQL database, and I need it to connect to Xero via OAuth 2.0, pull my invoice data, and render the results in a clean, browser-based dashboard. Here is the flow I’m after. When a user authorises through Xero OAuth 2.0, the app should store the access/refresh tokens securely in Postgres. On subsequent visits the server must refresh tokens automatically, query the Invoices endpoint, and pass the latest invoice records to the front-end. The dashboard only needs basic filtering (status, date range) and sortable columns, but it must be responsive and fast. Fetching and displaying data is the sole purpose—no record creation or updates for now. You’ll be working entirely inside Replit, so knowledge of its secrets manager and deployment quirks is important. Please write clear, documented code (ES modules preferred) and include a concise read-me so I can reproduce the OAuth setup on a fresh Replit if needed. Deliverables: • Node.js backend logic for OAuth 2.0 handshake, token refresh, and “Invoices” GET calls • PostgreSQL schema or migration for token storage • Minimal front-end dashboard (vanilla JS or React) that consumes the invoice JSON served by the backend • Clear setup instructions and brief testing notes I’m happy to answer technical questions quickly and will test against my live Xero tenant as soon as you push the repo.