Get S3 Summary

Client-level S3 rollup plus its per-grant rows.

available is the ledger balance (accrued − consumed) — the four wallet tiles. reserved and remaining are the apply header's extra two: tokens already applied to upcoming invoices, and what is left to apply after them.

allocated sums the per-grant rows, each already net of its cancelled slices, so it is not the total ever awarded to this client.