The on-disk shape of `__manifest` is reconciled with the binary via a single
stamp + dispatcher in `db/manifest/migrations.rs`:
- `INTERNAL_MANIFEST_SCHEMA_VERSION = 2` declares the shape this binary writes.
- The on-disk stamp `omnigraph:internal_schema_version` lives in the manifest
dataset's schema-level metadata (Lance `update_schema_metadata`).
- `migrate_internal_schema(&mut dataset)` walks `match`-arm steps forward from
the on-disk stamp until it matches the binary, then returns. Idempotent.
- `init_manifest_repo` stamps the current version at creation; the publisher's
open-for-write path runs pending migrations before reading state. Reads
stay side-effect-free.
- Forward-version protection: a stamp higher than the binary's known version
triggers a clear "upgrade omnigraph first" error so an old binary cannot
clobber a newer schema.
Self-heals existing pre-MR-766 deployments by auto-applying the v1→v2 step:
the `lance-schema:unenforced-primary-key` annotation on `__manifest.object_id`
that engages Lance's row-level CAS at commit time. New repos created via
`init` are stamped at v2 immediately and don't need migration.
Adding a future on-disk shape change is one constant bump, one match arm in
`migrate_internal_schema`, and one test — no new branches in unrelated code
paths. Code outside the migration module never inspects the stamp.
New tests in `manifest/tests.rs`:
- `test_init_stamps_internal_schema_version`
- `test_publish_migrates_pre_stamp_manifest_to_current_version`
- `test_publish_rejects_manifest_stamped_at_future_version`
Docs: `docs/storage.md`, `docs/maintenance.md`, `docs/constants.md` updated
per the AGENTS.md maintenance contract.
- storage.md: document the row-level CAS annotation on `__manifest.object_id`
and the `expected_table_versions` OCC contract on `ManifestBatchPublisher::publish`.
- errors.md: list `ManifestConflictDetails` and its variants alongside `ManifestError`.
- constants.md: add `PUBLISHER_RETRY_BUDGET = 5`.
Per AGENTS.md "Maintenance contract": new schema construct, new constant, and
new typed error shape all need to ship with the source change.
Splits the 990-line AGENTS.md into a 184-line map (architecture,
where-to-find index, always-on invariants, capability matrix,
maintenance contract) plus 18 new docs/*.md files holding the deep
content per topic (storage, schema and query languages, indexes,
embeddings, branches/commits, runs, merge, changes, execution, policy,
server, CLI reference, audit, errors, CI, constants, v0.3.1 notes).
Adds scripts/check-agents-md.sh and a check_agents_md CI job that
verifies every docs/ link in AGENTS.md resolves and every doc in the
canonical set is linked. CLAUDE.md remains a symlink to AGENTS.md.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
