v0.4.0

The module is reduced to the SQL infrastructure service over the sqlate library
(github.com/standards-lab/sqlate), which owns everything from the .sql file to the scanned
row. A composition root wraps the pool this module constructs with sqlate.Wrap and the engine's
dialect from sqlate/postgres, compiles its statements through sqlate/query, and migrates
through sqlate/migrate.

Changed

• Breaking: the ast, operation, exec, and seed packages are removed. Authored SQL
  files over sqlate/query replace the statement vocabulary and the runners; sqlate/migrate
  and a consumer's own seed statements replace seed.
• Breaking: the Session, Tx, and Dialect types, ExecTx, and the Provider constant
  are removed, with the DB.Dialect, DB.Begin, DB.QueryContext, DB.QueryRowContext, and
  DB.ExecContext methods. The sqlate package owns the session and the dialect.
• Breaking: the four constraint-class sentinels, ConstraintError, and ErrVersionMismatch
  are removed. The sqlate package owns the constraint classes and sqlate/query the version
  mismatch; the sqlate/postgres dialect classifies driver errors inside the session.
• Breaking: New is New(conn *sql.DB, cfg Config) *DB. It panics on an unfinalized
  config or a nil pool, the wiring rule the package comment now states.
• The build task and the CI build step run each module with GOWORK=off, so a pin that no
  longer builds fails rather than being masked by the committed go.work.

Added

• admin: the database admin service. New takes the pool's lifecycle object, the sqlate
  session, a prebuilt migrate.Migrator, and the pattern catalog; Options carries a
  Seeder, a Registry of compiled statements, a logger, and the seed switch. Register
  declares the service at lifecycle Stage 1; Start verifies the history, applies a pending
  set, verifies the seeder, and seeds when enabled. Verify, Status, Up, Down, Steps,
  Force, and Seed are triggers over the library's functions; Catalog and Statements
  read build-time state; Diagnose pings, reads the server's version through the dialect's
  optional Versioner capability, and reports the pool's counters.
• The base module requires github.com/standards-lab/sqlate v0.1.0, a standard-library-only
  module.