SQLx offline query cache (`.sqlx/`) is committed so
`SQLX_OFFLINE=true cargo check` works without a live database.

Generated with `cargo sqlx prepare` against a live testcontainers
database; CI runs `cargo sqlx prepare --check`.

This placeholder keeps the directory committed while the cache is empty
(todo 1 scaffolding has no queries yet; the first query-bearing todo
populates it).
