AI Changelog Aggregator

Honor the OPENAI_BASE_URL environment variable for the built-in openai model provider: https://github.com/openai/codex/pull/1487
Support model_reasoning_effort and model_reasoning_summary when defining a profile thanks to https://github.com/openai/codex/pull/1484
Add a completion subcommand to the CLI in https://github.com/openai/codex/pull/1491 so we can ultimately add generate_completions_from_executable() to our Homebrew formula: https://github.com/Homebrew/homebrew-core/blob/main/Formula/c/codex.rb