Opus 4.8 audit of Fable's slice-1 scaffold + authorized hardening (Step 2).
Stacked on feat/adr-0246-slice1-scaffold. Not a PR, not merged, no status flip.
AUDIT (Step 1) — VERDICT PASS. Re-derived A(F)/d_orth/d_stab/typed channels from
§3.1/3.2/3.6 independently: BIT-EXACT vs impl (0.00e+00). Confirmed in code (not
just comments): H_id={I} locked (singleton hardcoded, no enlargement path); path
composes lawful only, refused=break marker, never raw, never soft-I; no §7 scope
creep; serve byte-identity. Finding F1 (doc, not bug): composition uses the raw
CERTIFIED action (required for §6.2 accumulation, else A_path≡I detects nothing) —
now documented for ADR ratification.
HARDENING (Step 2):
§3.7 pure surface (identity_action.py): AdmissionPolicy (calibrated flag),
evaluate_admission (admit-or-abstain, no corrector); CERTIFIED_GAMMA_ID pinned
== identity._WAVE_LEAKAGE_BOUND; all other bounds UNCERTIFIED placeholders.
§3.7 SERVE WIRING (Steps 2.1/2.2): new default-off flag identity_action_surface
(config); threaded chat/runtime -> check -> _wave_field_score; refusal folds
into flagged -> existing would_violate/conjugate_correct abstains; IdentityScore
gains action_surface_active/d_orth/d_stab (legacy defaults). Flag-off is
byte-identical (D4 gate surfaces green unchanged; smoke 176 post-wiring).
§6.3 DISCRIMINATION REPORT (evals/adr_0246_discrimination) — HONEST numbers:
benign pass 0.00, false refusal 1.00, adversarial detect 1.00, control pass
1.00; d_stab AUC 0.375 (95% CI [0.15,0.62]) — BELOW chance. Benign cognition
sits ~18x farther from the frame (mean d_stab 27.8) than the attacks (1.55).
The gate refuses everything and does NOT discriminate; must stay off; usable
separation needs the §11 grounding work, not threshold tuning. Claims language
enforced: 'lawfulness relative to the declared frozen frame', NOT 'semantic
inalienability'.
Ledger raw-sneak hardening test (Step 2.3): mixed lawful/refused sequence must
equal the lawful sub-product, fails if raw sneaks into A_path_lawful.
Handoff to Sonnet: §4.1 per-turn record, path-ledger serve integration, ADR-0246
body + acceptance packet (Proposed, no self-Accept), §11 grounding-feasibility.
[Verification]: uv run core test --suite smoke -q => 176 passed (post-wiring);
ADR-0246 suites 80 passed; egress wiring + D4 gate surfaces 47 passed
(byte-identity); §6.1/6.2 eval 14/14; discrimination report numbers above.
See docs/audit/adr-0246-slice1-opus-audit-and-hardening.md + run log.
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