QuantConnect/Lean ? reverse-engineered prompt

I want you to build an open-source algorithmic trading engine. It needs to be a professional-grade platform where I can write trading strategies in either C# or Python. The main goal is to be able to develop an idea, backtest it against historical data, and then deploy it for live trading.

The engine should be event-driven and support a wide range of markets, including US stocks, forex, crypto, options, and futures. I want a simple but powerful command-line tool to manage everything. For example, there should be commands to create a new project, run a backtest from the terminal, optimize strategy parameters, and launch a live trading bot. It should also integrate a research environment, maybe using Jupyter, so I can explore data and develop models before turning them into full strategies.