empty payload branches

// Test: Multiple branches with BOTH having empty payloads
// This tests switch emission for empty union variants
// Previously: emitter would generate |name| capture even for empty payloads
// Fixed: emitter now generates => { without capture for empty payloads

~import std/io

// Event with two branches, BOTH empty (no payload fields)
~event check-value { n: i32 }
| positive
| non-positive

~proc check-value|zig {
    if (n > 0) {
        return .{ .positive = .{} };
    } else {
        return .{ .non_positive = .{} };
    }
}

// Test: handle both empty branches
~check-value(n: 42)
    | positive |> std/io:print.ln("42 is positive")
    | non-positive |> std/io:print.ln("42 is not positive")

~check-value(n: -5)
    | positive |> std/io:print.ln("-5 is positive")
    | non-positive |> std/io:print.ln("-5 is not positive")

~check-value(n: 0)
    | positive |> std/io:print.ln("0 is positive")
    | non-positive |> std/io:print.ln("0 is not positive")