Fix mobile validation, cascade delete for businesses/categories, and DB error handling.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/modules/businesses/businesses.service.ts

@@ -6,7 +6,8 @@ import {
   NotFoundException,
 } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
-import { Repository } from 'typeorm';
+import { DataSource, Repository } from 'typeorm';
+import { deleteBusinessCascade } from '../../common/utils/business-cascade.util';
 import { BusinessCategoryEntity } from '../../entities/business-category.entity';
 import { BusinessEntity } from '../../entities/business.entity';
 import { UserEntity, UserRole } from '../../entities/user.entity';
@@ -29,6 +30,7 @@ export class BusinessesService {
     private readonly categoryRepo: Repository<BusinessCategoryEntity>,
     @InjectRepository(UserEntity)
     private readonly userRepo: Repository<UserEntity>,
+    private readonly dataSource: DataSource,
   ) {}
 
   async findAll(filters: FindAllFilters): Promise<BusinessEntity[]> {
@@ -111,10 +113,11 @@ export class BusinessesService {
   }
 
   async remove(id: string): Promise<void> {
-    const result = await this.repo.delete(id);
-    if (!result.affected) {
-      throw new NotFoundException('Business not found');
-    }
+    await this.findOne(id);
+
+    await this.dataSource.transaction(async (manager) => {
+      await deleteBusinessCascade(manager, id);
+    });
   }
 
   async assignOwner(