Run a Monte Carlo simulation for a specified cryptocurrency pair (e.g., BTC/USD, ETH/USDT, SOL/USD).
The goal is to forecast the possible price range for the next N days using a geometric Brownian motion model.
The output should include:

A CSV file with percentile summaries (5%, 25%, 50%, 75%, 95%) per day.

A PNG chart visualizing sample price paths and percentile curves. . . .