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>
