This commit introduces a lightweight, browser-based auction system.
It consists of two main components that communicate in real-time using the `BroadcastChannel` API, enabling a serverless
front-end experience:
- `display.html`: The public-facing screen for attendees. It shows the current item, price with smooth animation, and
deal announcements. It automatically generates a unique session ID.
- `control.html`: The auctioneer's control panel. It uses the session ID from the display page to connect. It allows for
managing the auction flow, including loading items from a CSV, starting bids, updating prices, and finalizing sales.
