Make Arvan DNS updates opt-in and persist English user names.

Domain add/edit only upserts Arvan records when updateDns is true, and super-admin user PATCH now accepts firstNameEn and lastNameEn.

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

src/business-admin/business-admin.service.ts

@@ -548,7 +548,7 @@ export class BusinessAdminService {
       },
     });
 
-    const dnsError = await this.applyArvanDns(host);
+    const dnsError = dto.updateDns ? await this.applyArvanDns(host) : null;
 
     return {
       ...domain,
@@ -648,7 +648,7 @@ export class BusinessAdminService {
       },
     });
 
-    const dnsError = await this.applyArvanDns(host);
+    const dnsError = dto.updateDns ? await this.applyArvanDns(host) : null;
 
     return {
       ...updated,