loadCrossRepoReceipts orders by mergedAt DESC NULLS LAST but the type guarantees mergedAt is non-null for merged rows — NULLS LAST is dead code that hides invariant violations

Opus finding

loadCrossRepoReceipts orders by mergedAt DESC NULLS LAST but the type guarantees mergedAt is non-null for merged rows — NULLS LAST is dead code that hides invariant violations

• apps/web/lib/receipts.ts:135-155

Since status='merged' rows are expected to have non-null mergedAt, `NULLS LAST` is meaningless under the intended invariant and quietly hides any rows that violate it (they'd sort to the end and may get cut by LIMIT). Combined with the lack of a CHECK constraint (above), this is a defensive but silent mask.