openai/gpt-5.2-chat → A (8:1)

Side A makes concrete code improvements across the workspace: fixes clippy warnings (e.g., replacing match destructuring with direct let patterns), improves API usage (`is_some_and`, removing unnecessary borrows), adds a missing `#[test]`, introduces a type alias to simplify a complex return type, and allows dead code in shared test helpers to keep CI clean. Side B only adds informal notes and a planning document with no executable code or integration, providing no immediate impact on the codebase.