012 constructor consumes type registry

// PINS: the constructor's CONSUMPTION path — deriving a NEW struct type from an
// EXISTING type's fields. `std/types:fields-of(Player)` is a comptime traversal
// SOURCE (emergent iteration, like ~for — it pulses `! each f` over Player's fields,
// not an iterator fed to a loop); `field(f.name, f.type)` rebuilds each into
// PlayerSnapshot. Round
// reads the fields via Zig `@typeInfo` in the lowered code — NO registry (generation
// AND consumption both lower to `@Type`; Zig is the registry for a lowered type). A
// Koru-level type registry — reasoning about type SHAPE at Stage C, before Zig — is
// the north star this consumption path gestures at, NOT what this pin requires.
// `f.name` / `f.type` are the reflected field spec. Surface PROVISIONAL.

~import std/constructor
~import std/types

const std = @import("std");

~std/types:struct(Player) {
    name: []const u8,
    health: i64,
}

~std/constructor:struct(PlayerSnapshot)
! construct |> std/types:fields-of(Player)
    ! each f |> std/constructor:field(f.name, f.type)

~event main {}

~proc main|zig {
    const s = PlayerSnapshot{ .name = "Alice", .health = 100 };
    std.debug.print("{s} {d}\n", .{ s.name, s.health });
}

~main()