Worked on targeted documentation improvements, regression testing, and repository hygiene across the rust-lang/rust and cpprefjp/site repositories. Enhanced the Path::join documentation in Rust to clarify Windows-specific behavior and its relationship to PathBuf::push, improving clarity for developers working with file paths. Added regression tests in Rust to verify linting, keyword handling, and foreign type operations, strengthening language reliability. Improved and centralized documentation for standard exception types in C++ within cpprefjp/site, including usage examples and cross-links. Addressed repository hygiene by updating .gitignore to exclude Python __pycache__ artifacts, ensuring cleaner version control. Utilized C++, Rust, and Python throughout.