084 effect branch resume numeric

// Test: effect-branch handler produces a numeric resume value with `->`.
//
// The effect is declared `-> i32`, so the arm produces with `-> 42`. Same
// shape as the string literal in 400_082, just confirms primitives flow.

~import std/io

~pub event query { question: []const u8 }
! ask []const u8 -> i32
| done i32

~proc query|zig {
    const answer = ask(question);
    return .{ .done = answer };
}

~query(question: "The Answer?")
! ask _ -> 42
| done a |> std/io:print.blk {
    The Answer is {{ a:d }}
}