The 2026-05-19 design review's P0 #1 finding:
> CognitiveTurnPipeline can replace a useful runtime surface with
> placeholder prose.
Evidence at core/cognition/pipeline.py:147-149 (pre-fix):
if realized_plan.surface and not gate_fired:
surface = realized_plan.surface
articulation_surface = realized_plan.surface
The override gate was JUST "non-empty + gate didn't fire". No
usefulness check. Result: a realizer output of
"Truth is defined as ..." (with <pending> rendered as ...) silently
overrode a perfectly-grounded runtime pack surface, and the runtime
audit log still held a third surface.
Fix: gate the override through ``_is_useful_surface`` from
generate/intent_bridge.py — the same predicate that already gates
the bridge's articulate_with_intent fallback path. An ungrounded
realizer surface cannot honestly override a grounded runtime
surface. When the realizer cannot produce a useful surface, we
keep the runtime answer the user sees.
Measured lift on the warmed_session_consistency lane (3 of its 4
metrics):
BEFORE AFTER
no_placeholder_rate 0.4444 → 1.0000
telemetry_consistency_rate 0.4444 → 1.0000
warm_grounding_stability 0.0000 → 0.0000 (separate bug — see below)
The two metrics that flipped to 1.00 are now CI-pinned in
tests/test_warmed_session_lane.py:
TestPipelineOverrideGateInvariants — any future weakening of the
override gate fails the suite immediately.
Cognition eval byte-identical:
public: 100 / 100 / 91.7 / 100
holdout: 100 / 100 / 83.3 / 100
KNOWN FOLLOW-UP — not in this commit:
warm_grounding_stability remains 0.0 because of a SEPARATE bug
the warmed lane surfaces:
Turn 1: "What is truth?" -> pack-grounded ("truth — pack-grounded
(en_core_cognition_v1): cognition.truth; ...")
Turn 2: "What is truth?" -> vault-grounded ("Truth infer.")
After turn 1 ingests pack content into the vault, turn 2's gate
source flips from ``empty_vault`` to ``vault``, so the runtime's
``_maybe_pack_grounded_surface`` dispatcher is bypassed entirely
and the field-walk path produces gibberish ("Truth infer.").
This is the SurfaceSelector-shaped problem from the design review:
pack-grounding should fire by intent shape and lemma residency, not
by vault gate state. Fix scope crosses runtime.py:chat() + the
vault gate logic; deferred to its own commit / design proposal
rather than absorbed here.
The warmed lane already records the metric (0.0 baseline) so when
the fix lands it shows up as a measurable lift.
c3e2a229a8