Instrument: the arithmetic-chain domain now routes each real GSM8K dev case to
Tier-1 (single-accumulator) or Tier-2 (multi-register / summation) and compares
the corridor to a symbolic fold of the SAME compiled program. Recorded coverage
moves 26/50 -> 50/50, 0 refused, PARITY (wrong=0) — the measurement catching up
to the capability. Scope note corrected (full holdout closed; remaining frontier
= derived-operand transfers + non-affine kinds + >5-atom deduction, all 0 on this
holdout). Updated the ADR-0249 instrument test pins (26->50, refused 24->0).
ADR-0250 (Status Proposed, no self-Accept; §10 ruling awaits Shay) + acceptance
evidence: multi-register model, relative conservation, atomicity, certified
summation, chain-of-custody, and the full-holdout 50/50 wrong=0 result.
10/10 instrument pins green.
[Verification]: uv run python -m pytest tests/test_adr_0249_arithmetic_lift.py tests/test_generalized_lift_instrument.py -q
