The code was formatted by hand, and `cargo fmt --check` differed in 866 places. rustfmt.toml keeps the house's long lines (120) and short expressions on one line, which halves what changes; this commit is only what rustfmt does with it, and is named in .git-blame-ignore-revs. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>