Every section banner dies (103 -> 0) across test/lang, the observer
suites, the C carriers, and the five comment-heavy corpus fixtures;
banner provenance (#N cites, carrier numbers, repair-cluster labels)
folded into headers or adjacent WHY comments. Narration deleted; row
provenance, ref cites, divergence pins, and layout contracts kept
(fwd-ref decl-order guards and bootstrap-gate corpus rationale
restored where the sweep over-cut). Comment-only proven: all 3742
wwbuild workdir .s byte-identical before/after; test-commit and
test-byteid (161 lang + 1399 data, 0 pinned-divergent) green.
The N_TRYUNW/N_TRYPROP success shuffle materialized {ptr,len,cap} into {AX,BX,CX} only when the success variant was a str; a slice success got only MOVQ DX,AX (ptr), leaving every slice-unwrap consumer (call-arg push, let-receive store, ident-source) reading junk .len/.cap — silent on BOTH stages (byte-id blind, cstage not the oracle). Widen the success gate to type_isstr||type_isslice (cstage) / typeisstr||typeisslice (wwstage) at all four shuffle sites; str and slice share the identical 24B header shuffle. Stays str||slice-specific — a struct success variant uses a different {AX,DX,CX} ABI (task #12). Value-asserting pin (len!=cap, poison-decoy) reddens under each stage's independent revert.
Follows #6 Mech A (Fix-R); order forced (C1 first or the slice call-arg push reddens byte-id).
