fix: eliminate untyped repository returns and standardize DomainException usage across all handlers

- Create typed DTOs (ListingDetailData, ListingSearchItem, ListingSellerItem) for repository read methods
- Replace all Promise<any> and PaginatedResult<any> with concrete types in repository interface and implementation
- Remove `as any` casts in search params by using Prisma enum types (TransactionType, PropertyType)
- Migrate all 16 handlers from NestJS built-in exceptions to domain exceptions (NotFoundException, ValidationException, etc.)
- Add CONTRIBUTING.md documenting error handling convention
- All 230 tests pass, typecheck clean

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

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

@@ -1,15 +1,11 @@
-import {
-  ForbiddenException,
-  Inject,
-  NotFoundException,
-} from '@nestjs/common';
+import { Inject } from '@nestjs/common';
 import { type IQueryHandler, QueryHandler } from '@nestjs/cqrs';
+import { NotFoundException, ForbiddenException } from '@modules/shared/domain/domain-exception';
 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;
@@ -32,17 +28,11 @@ export class GetPaymentStatusHandler implements IQueryHandler<GetPaymentStatusQu
   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',
-      });
+      throw new NotFoundException('Payment', query.paymentId);
     }
 
     if (payment.userId !== query.userId) {
-      throw new ForbiddenException({
-        code: ErrorCode.FORBIDDEN,
-        message: 'Bạn không có quyền xem thanh toán này',
-      });
+      throw new ForbiddenException('Bạn không có quyền xem thanh toán này');
     }
 
     return {