Design the frontend architecture for a production trading system UI. Assume the product is a web trading interface with areas such as a market chart, order book, recent trades, buy/sell order-entry form, user balances, open orders, and execution status. Focus on the frontend architecture rather than the backend matching engine. Discuss the design from the following angles: - Framework and rendering strategy. - UI component library or design system choices. - State management. - Real-time data flow. - Error handling and loading states. - Performance and reliability. - Security. - Testing and observability. Be prepared to answer follow-up questions about tradeoffs and edge cases.