(** Versioned schema migrations for the SQLite store.

    Each migration is a numbered, named set of statements. A [schema_migrations]
    ledger records which versions a database file already carries, so applying
    on connect runs only the migrations the file is missing and never repeats
    one. Every statement still uses [IF NOT EXISTS], so a database created by an
    earlier, ledger-less build stays safe.

    Includes the [dream_session] table {!Dream.sql_sessions} expects. *)

type migration = { version : int; name : string; statements : string list }
(** One migration: a version, a human name, and the ordered statements it runs.
*)

val migrations : migration list
(** Every migration, in ascending version order. *)

val apply : (module Caqti_lwt.CONNECTION) -> (unit, Caqti_error.t) result Lwt.t
(** Create the ledger, then apply every migration not yet recorded, each inside
    a transaction. Idempotent across reconnects. *)

val statements : string list
(** Every migration's statements, in order, exposed for documentation and tests.
*)