## Summary - Prioritize provider-specific API keys over default Codex auth when building requests - Add test to ensure provider env var auth overrides default auth ## Testing - `just fmt` - `just fix` *(fails: `let` expressions in this position are unstable)* - `cargo test --all-features` *(fails: `let` expressions in this position are unstable)* ------ https://chatgpt.com/codex/tasks/task_i_68926a104f7483208f2c8fd36763e0e3