Baseline decision artifact at main@5ada1392 (post-#616). Records the R1
4/0/6 state per-fixture: the 4 admitted semantic families and the invariant
protecting each, and a classification of the 6 refusals — 2 pure phrasing
gaps (r1-03/r1-04 aggregate-query), 1 real reverse-solve capability (r1-07),
and 3 correct wrong=0 boundaries that must stay refused (r1-08/09/10).
Source-verified against the merged reader (refusal codes + line refs) and
the live lanes (setup 4/0/6, answers 4/0/6 setup_wrong/gold_error 0,
15-case 15/0/0). Docs-only; no code, no serving lane, no SHA-lane content.
