For agents, on top of README.md, which they read first.

• The invariants for these files are one folder up, in crates/postjevsql-sidecar/CLAUDE.md, which loads with this one.
• Keep deny_unknown_fields on every config struct. A misspelt sslmode that parsed as absent would fall back to a default without a word.
• A rename is recognised only in the one unambiguous case (one column gone, one new at the same position, same type and nullability). Widening the heuristic risks renaming the wrong column under a view; a drop and an add is refused safely instead.