Mirror the shared Swift rules canon (rules-swift, commit 4ebb892) into
docs/rules-swift/ as a read-only reference alongside the repo's tailored
docs/rules/. PROVENANCE.md records the source, commit, and what was
included or excluded; the upstream repo's own VCS, CI, and lint tooling
is omitted as machinery rather than rule content.
Exclude the vendored tree from the style gate (scripts/check-style.sh)
and the pre-commit hook: the canon's enforcement docs quote the
forbidden attribution phrases to define them, the same reason the
repo's own enforcement files are already excluded.