Both carriers were already slim: the r76_def_widen_* byte-id legs are
owned by the test-data-byteid blanket, 783's positive byte rows by the
r78_amp_fn_assign_* fixtures plus that same blanket, and its symmetric
non-tagged rejects by the corpus //ww:error fixtures. The unowned
remainder is three cstage-only loud-rejects (the 760 narrowing def-ref
and 783's two tagged-slot rows); the wwstage over-accepts (no def-init
assignability check; #214 void-variant leniency) are documented at the
site per the residual audit, never asserted as desired — the rows
graduate to //ww:error fixtures when the wwstage side tightens.
Bundled: one file, one concern (cstage-reject pins awaiting wwstage
graduation).
