List read-only invoice payment collection gates

Returns invoice payment collection gates for all platform launch verticals when the authenticated automation client has platform.billing_owner_visibility.read. External URL: /v1/providers/current/invoice-payment-collection-gates. Current Next.js implementation path: /api/platform/v1/providers/current/invoice-payment-collection-gates. This read-only route does not require Idempotency-Key; it exposes payment collection prerequisites, blocked payment-provider calls, hidden payment-method payload posture, missing refund/dispute/support/audit prerequisites, blocked 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, payment method payloads, or processor payloads, sends invoices, records delivery receipts, collects payments, mutates refunds or disputes, enforces quota, suspends credentials, or calls external finance providers.