036 destructure when guard boolean and

// FRONTIER PIN: boolean connective `and` inside a when-guard, over
// destructured names. The expression parser carries and/or keywords
// (src/expression_parser.zig matchKeywordBoundary "and") but a full
// corpus sweep (2026-07-04 QA) found ZERO passing test exercising a
// Koru-level boolean connective anywhere — every corpus `when` guard is
// a single comparison, and every `and` in the tree lives inside raw
// |zig proc bodies. Plumbing-exists-but-never-exercised = ungrounded.
// This pin grounds it (or names the gap, if red): compound selection is
// the store-query guard shape (`when hp > 40 and kind == 1`, 690_005).
//
// Same coverage shape as 020_035: unguarded fallback sibling (210_085
// rule, 400_089 rescue).

~import std/io

~pub event scan-pairs {}
! pair { a: i64, b: i64 }
| done

~proc scan-pairs|zig {
    pair(.{ .a = 1, .b = 2 });
    pair(.{ .a = 3, .b = 4 });
    pair(.{ .a = 5, .b = 6 });
    return .done;
}

~scan-pairs()
! pair { a, b } when a > 2 and b < 6 |> std/io:print.ln("big {{ a:d }}+{{ b:d }}")
! pair { a, b } |> std/io:print.ln("small {{ a:d }}+{{ b:d }}")
| done |> std/io:print.ln("done")