List and query invoices in the active scope

Returns the invoices issued for the active tenant/subscription scope as rendered by the Invoices page on route load: invoice number, description, billing period, subtotal/tax/total in ten-thousandths of the subscription currency's unit, lifecycle status and issue/due dates. This single endpoint also serves the search/filter/sort/paginate behavior (billing.invoice.search_filter_sort): the UI's status chips (ALL / PAID / UNPAID / OVERDUE / CANCELLED) map to the status query parameter and the free-text box maps to q (matched against invoice number and description); sort, order, page and pageSize apply standard collection semantics. Plain list = same call with no filter parameters. Validation: scopeId must reference a scope the caller can access (otherwise 403 FORBIDDEN); status must be one of PAID|UNPAID|OVERDUE|CANCELLED (otherwise 422 VALIDATION_FAILED); unknown sort keys map to 422 VALIDATION_FAILED. Async & state: Synchronous read; no state change. No SSE frames are emitted. Errors: 401 when unauthenticated; 403 when the caller lacks billing read access in the scope; 422 for malformed query parameters; 500 on backend read-model failure. Idempotency/Concurrency: Safe, cacheable; no idempotency key required.