List every bound customer wallet across all orgs with fill stats

Internal observability view. Joins customer_wallets (cross-tenant via ORG_BYPASS) with event_trades to surface fillCount + lastFillAt per wallet. Only public 0x… addresses are stored or returned — never private keys. The per-wallet fill scan is capped to prevent runaway queries on long-running orgs. Sortable: fillCount, lastFillAt, createdAt. Default sort: -fillCount. Default limit 50, max 500.