121 instantiate with named type

// Registry breakdown #2: a stamped type inside a CAPTURE CELL. The
// cell must NAME the generated type's identity rather than leaking the
// raw Zig type. With stamped names the cell
// type is just the name. Spelling PROVISIONAL (capture-cell typing of
// a Koru-minted type is itself part of the ask).

~import std/types
~import std/io
~import std/control

~std/types:struct(acc#i64) {
    total: i64,
}

~capture({ a: acc#i64{ .total = 0 } })
| as state |> for(&[_]i64{ 10, 20, 30 })
    | each n => captured { a: acc#i64{ .total = state.a.total + n } }
| captured final |> std/io:print.ln("Total: {{ final.a.total:d }}")