refactor(store): ordered metastore migrations · Pull Request #812 · tranquil.farm/tranquil-pds

lgtm, excellent addition, I have one idea that you don't have to listen to, but I think the test doesn't even have to exist if we catch that at compile-time in the first place, something like

crates/tranquil-store/src/metastore/mod.rs:47

const fn ascends(steps: &[(u64, UpgradeStep)]) -> bool {
    match steps {
        [a, b, rest @ ..] => a.0 < b.0 && ascends(rest),
        _ => true,
    }
}

const _: () = match UPGRADE_STEPS {
    [.., (CURRENT_FORMAT_VERSION, _)] if ascends(UPGRADE_STEPS) => {}
    _ => panic!("upgrade steps must be in the like, right order, ending at current version"),
}