feat(02-05): Payment model with FIFO allocation and void

- Add PaymentMethod (CASH, BANK_TRANSFER) and PaymentStatus (COMPLETED, VOIDED) enums
- Add Payment model with idempotency key, journal entry link, void fields
- Add PaymentAllocation model for FIFO invoice allocation tracking
- Add Payment/PaymentAllocation relations to Subscriber, Invoice, User
- Update TENANT_SCOPED_MODELS with "payment" and "paymentAllocation"
- Add payment/paymentAllocation query extensions in withTenantContext()
- Implement recordPayment() with FIFO allocation, overpayment credit balance
- Implement voidPayment() with reversing journal entries
- Implement getSubscriberPaymentHistory() with pagination
- Run migration: 20260304154606_add_payment_model

src/lib/prisma-tenant.ts

@@ -30,7 +30,7 @@ import { prisma } from "@/lib/prisma";
  * Extend this list as new models are added in later phases:
  * e.g., "subscriber", "invoice", "servicePlan", "payment"
  */
-export const TENANT_SCOPED_MODELS = ["user", "account", "accountingPeriod", "subscriber", "servicePlan", "tenantSettings", "journalEntry", "journalEntryLine", "invoice", "invoiceLine"] as const;
+export const TENANT_SCOPED_MODELS = ["user", "account", "accountingPeriod", "subscriber", "servicePlan", "tenantSettings", "journalEntry", "journalEntryLine", "invoice", "invoiceLine", "payment", "paymentAllocation"] as const;
 
 export type TenantScopedModel = (typeof TENANT_SCOPED_MODELS)[number];
 
@@ -848,6 +848,94 @@ export function withTenantContext(tenantId: string) {
           return query(args);
         },
       },
+
+      payment: {
+        async findMany({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findFirst({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findFirstOrThrow({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findUnique({ args, query }) {
+          if (args.where && "id" in args.where && !("tenantId" in (args.where as object))) {
+            return prisma.payment.findFirst({
+              ...args,
+              where: { ...args.where, tenantId },
+            });
+          }
+          return query(args);
+        },
+
+        async create({ args, query }) {
+          args.data = { ...args.data, tenantId } as typeof args.data;
+          return query(args);
+        },
+
+        async update({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async updateMany({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async count({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async aggregate({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+      },
+
+      paymentAllocation: {
+        async findMany({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async findFirst({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async create({ args, query }) {
+          args.data = { ...args.data, tenantId } as typeof args.data;
+          return query(args);
+        },
+
+        async createMany({ args, query }) {
+          if (Array.isArray(args.data)) {
+            args.data = args.data.map((item) => ({ ...item, tenantId })) as typeof args.data;
+          } else {
+            args.data = { ...args.data, tenantId } as typeof args.data;
+          }
+          return query(args);
+        },
+
+        async deleteMany({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+
+        async count({ args, query }) {
+          args.where = { ...args.where, tenantId };
+          return query(args);
+        },
+      },
     },
   });
 }