Allow add/edit domain to upsert tenant DNS on Cloudflare or Arvan.

Update DNS writes @, www, business, customer, and api records on the chosen provider instead of Arvan only.

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

src/business-admin/dto/update-domain.dto.ts

@@ -1,4 +1,4 @@
-import { IsBoolean, IsOptional, IsString, Matches, MinLength } from 'class-validator';
+import { IsBoolean, IsIn, IsOptional, IsString, Matches, MinLength } from 'class-validator';
 import { GIT_REPO_URL_RE } from '../../website-deploy/website-deploy.util';
 
 export class UpdateDomainDto {
@@ -6,11 +6,16 @@ export class UpdateDomainDto {
   @MinLength(1)
   host!: string;
 
-  /** When true, upsert Meshkee tenant records in Arvan DNS. */
+  /** When true, upsert Meshkee tenant records (@, www, business, customer, api). */
   @IsOptional()
   @IsBoolean()
   updateDns?: boolean;
 
+  /** DNS host for tenant records. Ignored unless updateDns is true. Default arvan. */
+  @IsOptional()
+  @IsIn(['arvan', 'cloudflare'])
+  dnsProvider?: 'arvan' | 'cloudflare';
+
   /** HTTPS or SSH git URL — when set, provisions storefront deploy on the websites VM. */
   @IsOptional()
   @IsString()