Four documents told different stories about the database schema. docs/DATAMODEL.md now owns the explanation and separates two things: the policy, which is unchanged (no supported upgrade path between versions; delete the local index with vaultik database delete and back up again), and the schema bootstrap that does exist (numbered files in internal/database/schema applied to a fresh database and recorded in schema_migrations). README.md and AGENTS.md are reworded to match and link there. AGENTS.md names the real file to edit, internal/database/schema/001.sql, and notes that the pre-1.0 disposability clause expires on tagging. No code changed. Judgement call: REPO_POLICIES.md still names a different schema file; it is cross-project policy and was left alone. model: claude-opus-4-8 (implementation, review); claude-fable-5-1 (merge)