feat(dashboard): architect End-of-Day summary and printable receipts

[0dillon]

Summary

Our merchant tooling lacks basic reconciliation features. At the end of a shift, merchants need a clear dashboard summarizing their daily volume and transaction counts to balance their books. Furthermore, customers frequently demand physical or digital receipts, which the app currently cannot provide.

We must architect a dedicated /dashboard route that aggregates local IndexedDB transactions into a clean, analytical 'End of Day' view. Additionally, a hidden, print-optimized CSS layout must be developed so merchants can trigger native browser printing (for bluetooth thermal printers) directly from the payment success screen.

Acceptance Criteria

• Build a /dashboard route displaying aggregated daily metrics.
• Design a clean, high-contrast UI for the receipt view.
• Implement an @media print CSS block that hides UI elements and formats the receipt.
• Add a 'Print Receipt' action to the transaction success modal.

Tech Stack

Next.js 14, React, Tailwind CSS.