052 reject user event in kernel

// TEST: aspirational - arbitrary user events should be rejected inside kernel scope

~import std/kernel

~std/kernel:shape(Body) {
    mass: f64,
}

~tor print-mass { value: f64 }
~proc print-mass|zig {
    const std = @import("std");
    std.debug.print("mass={d}\n", .{value});
}

~std/kernel:init(Body) {
    { mass: 1.0 },
    { mass: 2.0 },
}
| kernel k |> std/kernel:self { k.mass *= 2.0 } |> print-mass(value: k.ptr[0].mass)