feat: enhance onboarding forms with error handling and step persistence

apps/edr-freight-api/src/modules/companies/companies.service.ts

@@ -468,7 +468,7 @@ export class CompaniesService {
       const owner = await this.companiesRepo.findByTin(dto.tin);
       if (owner && owner.id !== company.id) {
         throw new ConflictException(
-          `Company with TIN ${dto.tin} already exists`,
+          `This TIN (${dto.tin}) is already registered to another company. Please check the number and try again.`,
         );
       }
       companyUpdates.tin = dto.tin;