Two 🧪 experimental QAT-W4A16 vLLM slugs (vllm/gemma-12b-qat-w4a16-single, vllm/gemma-31b-qat-w4a16-dual) + the standalone kv-calc gemma-12B int4 weight-pricing fix. 12B needs the gemma4-unified-vision-unquant sitecustomize workaround (vLLM #44494, both bugs, self-contained); 31B boots clean on stock vllm-gemma-stable. Full suite 42/0.