grim7/23/2026, 12:34:26 AM

Additive tables ai_review_usage, usage_counters, provider_costs_daily,
economics_daily per economics-surface-contracts.md. economics_daily uses a
null-safe unique index instead of a PK so the org_id null totals row is legal.
Service-layer writers are idempotent on their grain; backfill seeds
ai_review_usage from stored run_steps traces (both shapes), marked backfilled,
cost null, source prod (only the prod worker persists traces). Contracts hold
the shared constants and the pure source-derivation helper.

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