Returns the organisation's bank holdings, ONE line per connected bank (Mercury, Revolut (legacy), Meow, Wise, and one line PER Open Banking connection — an org may hold several banks, each named, with connection_id, per-connection fetched_at staleness and a shared_accounts count for an account two connections serve, rendered once; plus, when a bank needs reconnecting or was removed but still has booked cash, a residual Open Banking line with connection_id null whose name says "(reconnect required)" or "(no live connection)" — that line is NOT a connected bank), as a LIVE-VALUE view: each bank's booked cash balance — summed from its per-currency cash sub-accounts (e.g. Revolut GBP/EUR/USD collapse into a single Revolut total) — converted to the org home currency at TODAY's FX rate. This is the same number the human dashboard's "Bank balances" card shows. It is deliberately DISTINCT from the balance sheet's booked value (each transaction stamped at its own transaction-date rate); the difference is accumulated unrealized FX. The balance source is the booked general ledger (not a live provider API), so it is reproducible from the ledger. Every connected bank is listed including newly-connected zero-balance ones (book_cents 0). A bank whose currency has no available FX rate shows book_cents null (rate unavailable) rather than a misleading zero. Stripe is a payment processor, not a bank — its money is under get_account_balance / clearing, not here. For live provider API balances or Stripe/cash, use get_account_balance.
