Certify policyengine-uk 2.126.12 with policyengine-uk-data 1.58.0 #584

The UK bundle certifies policyengine-uk-data 1.58.0 with policyengine-uk 2.125.1 (#555). policyengine-uk 2.126.12, released on 2026-10-12, is the latest model. Its #2305 makes April-dated reforms apply: a reform keyed 2026-04-06.2100-12-31 scores in 2026-27 on 2.126.12, but scores nothing in that year on 2.125.1.

The data publisher's compatibility claim for 2.126.12 is in the 1.58.0 release manifest at HF commit 0aa3eee1 (policyengine/policyengine-uk-data-private). The commit message carries the evidence.

Certify the pair, pin policyengine-uk 2.126.12 (core stays 3.33.0), and regenerate the lockfile, TROs and pinned test constants together.