# v2.0.0-alpha.4 — git-baseline under the versioned schema contract

Extends the v2.0 schema work so `git-baseline.json` is a first-class versioned
artifact. No version bump and no breaking change — coverage only.

## Added

- `git-baseline.json` is now part of the versioned-schema registry
  (`ARTIFACT_SCHEMA_VERSIONS`). New baselines are written with a `schemaVersion`,
  and `relay-baton migrate` / `doctor --deep` report and normalize it like the
  other versioned artifacts.

## Changed

- `GitService.baselineSnapshot()` stamps `schemaVersion`; `GitBaseline` carries
  an optional `schemaVersion` (absent = legacy v1).

## Migration

- Pre-v2.0 `git-baseline.json` files (no `schemaVersion`) are detected as
  `legacy` and normalized by `relay-baton migrate --apply` (writes a `.bak`
  backup first). Idempotent.

## v2.0 status

Versioned-contract coverage now spans `session.json`, `checkpoints.jsonl`,
`git-baseline.json`, and the archive/bundle manifests. Remaining: bring
conversation events under the registry; per-artifact version bumps land as
breaking changes require them.