List read-only invoice delivery reconciliation gates

Returns invoice delivery reconciliation gates for all platform launch verticals when the authenticated automation client has platform.billing_owner_visibility.read. External URL: /v1/providers/current/invoice-delivery-reconciliation. Current Next.js implementation path: /api/platform/v1/providers/current/invoice-delivery-reconciliation. This read-only route does not require Idempotency-Key; it exposes delivery channel policy, draft-only destination metadata, missing receipt/acknowledgement/audit prerequisites, blocked invoice delivery/payment/quota/credential side effects, and next operator actions only. It never reads usage event tables or partner-facing billing tables, returns raw usage payloads, raw payment payloads, delivery receipt payloads, or recipient acknowledgement payloads, sends invoices, records delivery receipts, collects payments, enforces quota, suspends credentials, or calls external finance providers.