Exploratory structured-output recovery

This primary-only adapter was selected at step 50 using a fixed 12-example validation split. It was then evaluated once on a disjoint 12-example final test: deterministic schema-constrained generation parsed on 12/12 examples and exactly matched 3/12. The grammar admits all 248 valid schema combinations and does not use episode labels. Results are exploratory product-recovery evidence, not confirmatory, G3, behavioral-generalization, or mechanistic evidence.

Use exact base google/gemma-4-12B-it@707f0a3b8a3c7ad586ed01e27eafbad8a27dd0f7 and official Transformers commit 918dbf131d0df5b46e3f6e1d96174d62aa4d16d6. The upstream metadata reports Apache-2.0 and the model card separately links the Gemma 4 License. Review both before use. This repository contains no base weights. Public availability does not replace the linked upstream terms.