ONE channel's row state as the recall filter's ChannelSafe entry, or undefined when
the channel safes nothing — a channel that exempts nothing contributes no entry, exactly as
the old mask dropped a cleared channel rather than keeping a dangling row.
ONE channel's row state as the recall filter's ChannelSafe entry, or
undefinedwhen the channel safes nothing — a channel that exempts nothing contributes no entry, exactly as the old mask dropped a cleared channel rather than keeping a dangling row.