107 effect resume cannot issue obligation

// REQUIREMENT (effect-branch obligations, resume-issue FORBIDDEN — the mirror
// of 400_104): a `!` branch fires 0-to-N times. A resume type that ISSUES an
// obligation (`-> *R<state!>`) would hand the proc a fresh obligation per
// firing that escapes the firing un-discharged — incoherent. Must be rejected
// at the SIGNATURE level (NOT by inspecting any body). Symmetric to payload
// rules: resume-DISCHARGE (`-> *R<!state>`, 400_106) IS coherent (cleaned up
// in-scope, handed back); only resume-ISSUE is forbidden.
const std = @import("std");
const Resource = struct { id: usize };
var global_r = Resource{ .id = 99 };

~pub event borrow { n: usize }
! lend usize -> *Resource<active!>
| done usize
~proc borrow|zig {
    for (0..n) |i| {
        const r = lend(i);
        std.debug.print("got {}\n", .{r.id});
    }
    return .{ .done = n };
}