Git .mailmap Cleanup

Consolidates the many raw author identities that accumulate in a repository's git history (typo'd email domains, GitHub noreply addresses, AD/Windows usernames, mixed-case duplicates, "Lastname, Firstname" formatting) into one canonical Name <email> per real person, via a .mailmap file at the repository root.

Completion criterion

A first draft is done when every distinct identity in git log --format='%aN|%aE' | sort -u has either been merged into a canonical identity, or deliberately left unmapped because no confident identity resolution was possible. The task is fully done only after the user has reviewed and confirmed the uncertain merges (see Step 4).

Step 1 — Gather the raw identity list

git log --format='%aN|%aE' | sort -u