references/sources.md credits atlassian-gitflow-tutorial with contributing
the `--no-ff` requirement on Gitflow supporting-branch merges to
references/merging.md, and merging.md:14 does carry that claim — but the
file's own source_keys listed only context7-git-htmldocs, so the chain was
one-directional.
Surfaced by repairing validate-provenance.sh's Contributing-files parser
in the same series; this skill was one of seven whose sources.md the old
parser could not read, so checks 4 and 5 had never run against it.
Refs #99
Defame1297
c5b207aee8