pub const MIGRATION_SQL: &[(&str, &str)];Expand description
Additive migrations for pre-existing databases. Each entry is (sql, column)
where column is checked via PRAGMA table_info before running, so each
migration is idempotent — it runs only when the column is actually missing.
This never crashes on “duplicate column” even if _meta.schema_version lags
behind reality (e.g. a DB upgraded by an earlier build that added the column
without bumping the version).