vellum-migration-checklist

# Vellum Migration Checklist ## When A Migration Is Required Use a migration for shipped interfaces and persisted data: - DB schema changes, indexes, backfills, or persisted row shape changes. - Workspace file renames, moves, format changes, or namespace changes. - Stored config or data that existing installs must keep reading. Do not delete migration files. Migrations are append-only, even when their logic becomes obsolete. ## DB Migrations For DB migrations: 1. Add a new file under `assistant/src/memory/migrations/`. 2. Make it idempotent and safe to retry after interruption. 3. Register it in the migration index or registry used by DB init. 4. Update schema modules if the runtime schema changed. 5. Add or update a focused `db-*migration*.test.ts` test. Check for ordering drift and never reorder existing migrations. ## Workspace Migrations For workspace migrations: 1. Add a new numbered file under `assistant/src/workspace/migrations/`. 2. Append it to `WORKSPACE_MIGRATIONS` in `assistant/src/workspace/migrations/registry.ts`. 3. Make the migration idempotent. 4. Add or update a focused `workspace-migration-*.test.ts` test. Never reuse or reorder existing migration IDs. ## Release Notes Migrations Release notes are workspace migrations that append to `UPDATES.md`. Required: - Only add release notes for GA user-facing changes. - Do not add release notes for default-disabled, rollout-only, or feature-flagged features. - Include an HTML marker such as `<!-- rele...