feat(payments): implement Payments module with VNPay, MoMo, ZaloPay integration

Implement complete payment processing module following DDD + CQRS patterns:

- Domain layer: PaymentEntity aggregate, Money value object, domain events
- Infrastructure: PrismaPaymentRepository, VnpayService, MomoService, ZalopayService
- PaymentGatewayFactory pattern for provider abstraction
- CQRS Commands: CreatePayment, HandleCallback, RefundPayment
- CQRS Queries: GetPaymentStatus, ListTransactions
- Callback/webhook endpoints with signature verification and idempotency
- 23 unit tests covering domain, VNPay service, and gateway factory

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/modules/payments/application/queries/get-payment-status/get-payment-status.handler.ts

@@ -0,0 +1,59 @@
+import {
+  ForbiddenException,
+  Inject,
+  NotFoundException,
+} from '@nestjs/common';
+import { type IQueryHandler, QueryHandler } from '@nestjs/cqrs';
+import { GetPaymentStatusQuery } from './get-payment-status.query';
+import {
+  PAYMENT_REPOSITORY,
+  type IPaymentRepository,
+} from '../../../domain/repositories/payment.repository';
+import { ErrorCode } from '@modules/shared/domain/error-codes';
+
+export interface PaymentStatusDto {
+  id: string;
+  provider: string;
+  type: string;
+  amountVND: string;
+  status: string;
+  providerTxId: string | null;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+@QueryHandler(GetPaymentStatusQuery)
+export class GetPaymentStatusHandler implements IQueryHandler<GetPaymentStatusQuery> {
+  constructor(
+    @Inject(PAYMENT_REPOSITORY)
+    private readonly paymentRepo: IPaymentRepository,
+  ) {}
+
+  async execute(query: GetPaymentStatusQuery): Promise<PaymentStatusDto> {
+    const payment = await this.paymentRepo.findById(query.paymentId);
+    if (!payment) {
+      throw new NotFoundException({
+        code: ErrorCode.NOT_FOUND,
+        message: 'Không tìm thấy thanh toán',
+      });
+    }
+
+    if (payment.userId !== query.userId) {
+      throw new ForbiddenException({
+        code: ErrorCode.FORBIDDEN,
+        message: 'Bạn không có quyền xem thanh toán này',
+      });
+    }
+
+    return {
+      id: payment.id,
+      provider: payment.provider,
+      type: payment.type,
+      amountVND: payment.amount.value.toString(),
+      status: payment.status,
+      providerTxId: payment.providerTxId,
+      createdAt: payment.createdAt,
+      updatedAt: payment.updatedAt,
+    };
+  }
+}

apps/api/src/modules/payments/application/queries/get-payment-status/get-payment-status.query.ts

@@ -0,0 +1,6 @@
+export class GetPaymentStatusQuery {
+  constructor(
+    public readonly paymentId: string,
+    public readonly userId: string,
+  ) {}
+}

apps/api/src/modules/payments/application/queries/list-transactions/list-transactions.handler.ts

@@ -0,0 +1,58 @@
+import { Inject } from '@nestjs/common';
+import { type IQueryHandler, QueryHandler } from '@nestjs/cqrs';
+import { ListTransactionsQuery } from './list-transactions.query';
+import {
+  PAYMENT_REPOSITORY,
+  type IPaymentRepository,
+} from '../../../domain/repositories/payment.repository';
+
+export interface TransactionItemDto {
+  id: string;
+  provider: string;
+  type: string;
+  amountVND: string;
+  status: string;
+  providerTxId: string | null;
+  createdAt: Date;
+}
+
+export interface TransactionListDto {
+  items: TransactionItemDto[];
+  total: number;
+  limit: number;
+  offset: number;
+}
+
+@QueryHandler(ListTransactionsQuery)
+export class ListTransactionsHandler implements IQueryHandler<ListTransactionsQuery> {
+  constructor(
+    @Inject(PAYMENT_REPOSITORY)
+    private readonly paymentRepo: IPaymentRepository,
+  ) {}
+
+  async execute(query: ListTransactionsQuery): Promise<TransactionListDto> {
+    const limit = Math.min(query.limit ?? 20, 100);
+    const offset = query.offset ?? 0;
+
+    const { items, total } = await this.paymentRepo.findByUserId(query.userId, {
+      status: query.status,
+      limit,
+      offset,
+    });
+
+    return {
+      items: items.map((payment) => ({
+        id: payment.id,
+        provider: payment.provider,
+        type: payment.type,
+        amountVND: payment.amount.value.toString(),
+        status: payment.status,
+        providerTxId: payment.providerTxId,
+        createdAt: payment.createdAt,
+      })),
+      total,
+      limit,
+      offset,
+    };
+  }
+}

apps/api/src/modules/payments/application/queries/list-transactions/list-transactions.query.ts

@@ -0,0 +1,10 @@
+import { type PaymentStatus } from '@prisma/client';
+
+export class ListTransactionsQuery {
+  constructor(
+    public readonly userId: string,
+    public readonly status?: PaymentStatus,
+    public readonly limit?: number,
+    public readonly offset?: number,
+  ) {}
+}