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

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

src/modules/auth/auth.service.ts

@@ -12,6 +12,10 @@ import { JwtService } from '@nestjs/jwt';
 import { InjectRepository } from '@nestjs/typeorm';
 import { createHash, randomInt } from 'crypto';
 import { IsNull, MoreThan, Repository } from 'typeorm';
+import {
+  isValidIranMobile,
+  normalizeIranMobile,
+} from '../../common/utils/iran-mobile.util';
 import { AuthOtpEntity } from '../../entities/auth-otp.entity';
 import { UserEntity, UserRole } from '../../entities/user.entity';
 import { JwtPayload } from './auth.types';
@@ -200,8 +204,8 @@ export class AuthService {
   }
 
   private normalizeMobile(mobile: string): string {
-    const normalized = String(mobile ?? '').trim();
-    if (!/^(\+?\d{10,15}|09\d{9})$/.test(normalized)) {
+    const normalized = normalizeIranMobile(mobile);
+    if (!isValidIranMobile(normalized)) {
       throw new BadRequestException('Invalid mobile number');
     }
     return normalized;