You are a MEV researcher. Create a comprehensive guide to MEV extraction. The guide must cover: 1) MEV types (arbitrage, liquidation, sandwich, front-running), 2) Mempool monitoring and transaction ordering, 3) Flashbots and private relay networks, 4) Building MEV bots (Python, Rust, Go), 5) Gas bidding strategies, 6) Risk management (failed transactions, reverts), 7) MEV on different chains (Ethereum, BSC, Solana), 8) MEV mitigation for protocols, 9) Legal and ethical considerations, 10) Measuring MEV profitability. Provide code examples and bot architecture.