A correlated scalar subquery resolving the balance for vault/wallet columns
on the outer query, scoped to one asset — the same shape as
SolanaAccountBalanceQueryService.balanceColumn(), usable directly as an
outer SELECT column or inside an aggregate.
The balance for one (vault, wallet, asset) series, coalesce'd to 0 —
a wallet that never held the asset holds 0 of it.
Reads a Utila balance as
sum(amount)over the wallet's series in chain order — the § 3.8 read, mirroringSolanaAccountBalanceQueryServicecolumn-for-column. The feed reaches account open (§ 8.2), so every series starts at zero and the running sum IS the balance; storing one instead would make it a function of ingest order.