Closes audit Finding 3 (2026-05-20).
Pre-fix ``ratify_intent`` defaulted to ``threshold=0.0``, which admits
anything with non-negative ``cga_inner(prompt, anchor)`` — the field
gate (ADR-0022 §TBD-1) was structurally live but semantically
transparent. RATIFIED was logged on essentially every turn because
the CGA inner product over conformal space is not sign-symmetric.
Measurement (``scripts/calibrate_ratification_threshold.py``):
* Runs every cognition eval prompt (45 cases = 13 public + 13 dev +
19 holdout) through a primed ``CognitiveTurnPipeline``.
* Captures the actual ``cga_inner(prompt, anchor)`` score from the
pipeline's own ``_ratify_intent`` via a temporary spy on the
imported ``ratify_intent`` binding.
Observed distribution:
* 34 RATIFIED: min=+1.1039 p10=+1.1039 median=+2.6820 max=+5.7508
* 11 PASSTHROUGH (no vocab-grounded anchor available; score=0.0)
* 0 DEMOTED at any threshold ≤ 1.10
Threshold = 0.5 chosen as the calibrated default:
* Well below the empirical floor of 1.10 — every currently-passing
case stays RATIFIED, byte-identically.
* Clearly non-trivially positive — random Cl(4,1) inner products
fluctuate around zero, so 0.5 demands genuine correlation with
the anchor rather than passive non-negativity.
* Leaves headroom for the gate to actually demote weakly-aligned
off-corpus / adversarial prompts to UNKNOWN and route them
through the honest-refusal surface.
Verification:
* ``core eval cognition`` — public 100/100/91.7/100, holdout
100/100/83.3/100, dev 100/100/78.6/100 — byte-identical to
MEMORY baselines.
* ``core test --suite cognition`` — 120/0/1
* ``core test --suite smoke`` — 67/0
* ``core test --suite runtime`` — 19/0
* 2 new tests in ``tests/test_ratification_threshold_default.py``
pin both the constant and the signature default so a future
change cannot silently regress to ``0.0``.
