Why: A small max_tokens probe passed (small pre-deduction), suggesting the
account might have been topped up; redeploying with chat=claude-sonnet-4-6
and lightweight=deepseek-v4-flash showed full-turn pre-deduction (CNY 0.62)
still exceeds the CNY 0.48 balance - 6/6 turns quota-failed again.
Evidence: SELF - .task/model-ab/ab-sonnet-quota-blocked-r2.json + evidence
row; settings confirmed chat=claude-sonnet-4-6, lightweight=deepseek-v4-flash
on the instance before the run.
Impact: Still blocked on user-only payment input. Estimated CNY 50-100 covers
multiple full comparison runs on dmxapi; alternatively any OpenAI-compatible
provider key via ~/.secrets/abmodel or .env.dev SVC_MODEL_*.
