grounding: Stage 4 results - tiered_check clears every quality gate on Claude

H4 falsified as frozen (codex tiered lost one answerable cell its
holistic lane kept; the zero-call deterministic path fired only in the
probe because composition never produced a fully-quoted answer), and
recorded plainly. But the Claude lane of tiered_check is the first
configuration in four stages to clear every revised-rule quality gate
in one run: both housing support gates (weak Alabama rejected,
sufficient row rendered), all answerable cells rendered, 14/14 probe
allow/deny, no deterministic-tier false pass anywhere (both cleared
claims verified verbatim), fail-closed throughout - at one checker call
per cell, +8% output tokens and ~2.4x cache-write vs control. The
same-run holistic arm flipped BOTH housing decisions wrong, the third
weak-reference false accept across runs: stochastic same-model judging
confirmed, and the tiered arm's quote-preferring composition is the
only upstream delta that fixed it. Codex completed 18/18 non-control
cells (prior overloads were provider weather) but stays disqualified.

Promotion: claude-p + tiered_check recommended experimental lane, flag
off by default. Next stage's independent variables named: firmer
quote-anchored composition so the zero-call path carries real answers;
authority/current-law validation still untested. Receipts archived
under OpenLegalData with hashes (stage4-verifier-probes, stage4-h4);
pre-registration is b0338f65.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012AgUm5EcRKbT3duVFMbrQD