Switch migration commits to the real git user

[Soph]

https://entire.io/gh/entireio/cli/trails/379

Switch migration commits to the real git user

The migration and generation-repair tooling stamped every commit with Entire Migration <migration@entire.dev> — a domain we don't own, and a fixed tool identity that would block any future plan to sign these commits.

Every migration/repair commit now uses the migrating user's git user.name / user.email as author and committer, with a trailer block carrying the "this was tooling" signal:

Co-Authored-By: Entire Migration <migration@entire.io>
Entire-Migration: true

The trailer formatter lives in cmd/entire/cli/trailers/ alongside its peers (FormatStrategy, FormatCheckpoint, etc.) following the existing Format<Concept> convention. A checkpoint.CreateMigrationCommit(ctx, repo, tree, parent, subject) helper collapses what was six near-identical 4-line blocks across migrate.go and generation_repair.go into one expression each.

Commits

1. migrate: stamp commits with real git user, mark provenance via trailer — the substantive change.
2. trailers: move migration trailer formatting into the trailers package — pure relocation, byte-identical commit messages.
3. checkpoint: collapse migration commit sites via CreateMigrationCommit — call-site simplification.

Test plan

• mise run test — 5307 unit tests pass
• mise run test:integration — 340 integration tests pass
• Sanity-check a real entire migrate --checkpoints=v2 produces commits with the user's identity in author/committer and the trailer block in the message

---

Note

Medium Risk
Changes the author/committer and message format for migration/repair commits across v2 checkpoint migration and generation metadata repair, which could affect downstream tooling that inspects commit metadata. Functional behavior of checkpoint data writing is otherwise unchanged.

Overview
Migration and generation-repair tooling now creates commits with the current repo’s git user as both author and committer (enabling normal commit signing), instead of a fixed Entire Migration identity.

Tool provenance is preserved by adding a standardized trailer block (Co-Authored-By: Entire Migration <migration@entire.io> and Entire-Migration: true) via new trailers.FormatMigration, and call sites are simplified through checkpoint.CreateMigrationCommit (used by migrate.go, generation_repair.go, and v2 /main batch migration commits).

^{Reviewed by Cursor Bugbot for commit db0ad09. Configure here.}

[Copilot]

Pull request overview

Updates migration and generation-repair tooling to stop stamping commits with a fixed tool identity and instead use the repository’s configured git author/committer, while preserving “this was tooling” provenance via commit-message trailers.

Changes:

• Add a standardized migration trailer block (Co-Authored-By + Entire-Migration: true) via trailers.FormatMigration.
• Introduce checkpoint.CreateMigrationCommit(...) to centralize creation of migration/repair commits using the real git user identity.
• Switch migration + generation-repair call sites to use CreateMigrationCommit and ensure v2 /main batch writes include the migration trailer block.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
cmd/entire/cli/trailers/trailers.go	Adds migration trailer constants and FormatMigration formatter.
cmd/entire/cli/strategy/generation_repair.go	Uses CreateMigrationCommit for repair commits instead of a fixed tool author.
cmd/entire/cli/migrate.go	Removes fixed migration author constants and uses CreateMigrationCommit + real git user fallback for v2 writes.
cmd/entire/cli/checkpoint/v2_committed.go	Ensures migration-only batch commits carry the migration trailer block.
cmd/entire/cli/checkpoint/committed.go	Adds CreateMigrationCommit helper that uses repo git author and appends migration trailers.