LLM 0.37 switches its default model to the half-priced gpt-6-lunaMachine translation

Version 0.37 of the LLM CLI tool and Python library switches users who have not chosen a default model to gpt-6-luna, which costs half as much as the previous default, gpt-5.6-luna. It also adds gpt-6.1-sol and gpt-6.1-terra, plus a command for configuring models with OpenAI-compatible endpoints.