Engine reference kept in the repository. The documentation site — the Soli app in doc/ — is the one to update; when the two disagree, doc/ wins.

Only what has no page on the site lives here:

• SDBQL_REFERENCE.md — the complete SDBQL function and clause reference.
• BACKUP.md — physical checkpoints vs. logical dump/restore.

Seven other files were removed on 2026-09-20 (CLIENTS.md, FUSE.md, LUA_WEBSOCKET.md, SCHEMA_VALIDATION.md, SHARDING.md, TRANSACTIONS.md, lua_enhancements_progress.md). Six of them had not been touched since 2026-01-16 and were superseded by larger pages on the site — clients*, tooling, scripting-ws, api-collections, sharding, transactions. The seventh was a finished progress log. Recover any of them from git history if needed.