base/node ? reverse-engineered prompt

Build me a simple Docker based setup for running my own Base node.

I want it to let me choose either Base mainnet or Base Sepolia with an easy env file switch, then start up the execution and consensus parts together. It should ask for my Ethereum L1 RPC and beacon endpoints, use the right network settings automatically, and support optional things like Flashblocks, follow mode, pruning, and snapshots if I enable them.

Please make the startup as straightforward as possible, with clear defaults, a sample config for both networks, and a clean way to launch everything with docker compose. If anything about the current Base node setup has changed, look up the latest docs online and keep it aligned with what is actually used now.