Whether a hit's document is in the trash.
Not a property of a fragment. Trash is a flag on the manifest entry ([ADR-95](../../../docs/decisions/ADR-076-100.md#adr-95-trash--a-document-in-the-trash-is-a-flag-on-its-manifest-entry)), so it is a property of the document, resolved by joining the mirrored listing. Storing it on every fragment is what used to let a hit and its own document title disagree about whether they were binned.