103 resume body discard

// ============================================================================
// Test 510_103: MUST_ERROR — handler body is `_` discard but the branch
// declares a resume type. The handler fn must produce a value of the
// resume type; a discard produces nothing.
// ============================================================================

~pub tor prompt-user { question: string }
! ask string -> string
| done string

~proc prompt-user|zig {
    const reply = ask(question);
    return .{ .done = reply };
}

~prompt-user(question: "?")
! ask _ |> _
| done _ |> _