7cb7a9099c
- Add InvoiceStatus enum + Invoice + InvoiceLine models to schema - Add Invoice relation to Subscriber model - Add invoice/invoiceLine to TENANT_SCOPED_MODELS in prisma-tenant.ts - Add invoice/invoiceLine tenant-scoped query extensions to withTenantContext() - Run migration: 20260304152900_add_invoice_model - Create invoice-service.ts: generateInvoiceNumber, getInvoice, listInvoices, updateInvoiceStatus, markOverdueInvoices, voidInvoice (with JE reversal) - Create credit-service.ts: applyCredit() — DR Subscriber Credits (1150), CR AR (1100) - Create billing-service.ts: generateInvoiceForSubscriber (idempotent, JE + auto-credit), generateMonthlyInvoices (postpaid + prepaid timing with lead days)