feat: add custom domain support with SSL, DNS verification, and billing

Users can assign a custom domain to their app with automatic SSL via
cert-manager. Includes DNS verification flow (CNAME check), Persian
instructions, admin-configurable pricing via PlatformSetting, and
integration into the deploy wizard cost calculation.

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

backend/src/billing/billing.controller.ts

@@ -95,6 +95,24 @@ export class BillingController {
     return this.billingService.calculateCost(dto);
   }
 
+  // ─── Custom Domain Pricing ─────────────────────────────────────
+
+  @Get('settings/custom-domain-price')
+  @ApiOperation({ summary: 'Get custom domain monthly price' })
+  async getCustomDomainPrice() {
+    return this.billingService.getCustomDomainPrice();
+  }
+
+  @Patch('settings/custom-domain-price')
+  @Roles(UserRole.ADMIN)
+  @ApiOperation({ summary: 'Set custom domain monthly price (Admin)' })
+  async setCustomDomainPrice(@Body() body: { monthlyPrice: number }) {
+    if (body.monthlyPrice === undefined || body.monthlyPrice < 0) {
+      throw new BadRequestException('monthlyPrice must be a non-negative number');
+    }
+    return this.billingService.setCustomDomainPrice(body.monthlyPrice);
+  }
+
   // ─── Wallet (User) ───────────────────────────────────────────────
 
   @Get('wallet')

backend/src/billing/billing.service.ts

@@ -5,6 +5,7 @@ import { ServicePlan } from './entities/service-plan.entity';
 import { PricingRule } from './entities/pricing-rule.entity';
 import { Wallet } from './entities/wallet.entity';
 import { WalletTransaction } from './entities/wallet-transaction.entity';
+import { PlatformSetting } from './entities/platform-setting.entity';
 import { TransactionType, BillingCycle, PricingResourceType } from '../common/enums';
 import {
   CreateServicePlanDto,
@@ -23,6 +24,7 @@ export class BillingService {
     @InjectRepository(PricingRule) private ruleRepo: Repository<PricingRule>,
     @InjectRepository(Wallet) private walletRepo: Repository<Wallet>,
     @InjectRepository(WalletTransaction) private txRepo: Repository<WalletTransaction>,
+    @InjectRepository(PlatformSetting) private settingsRepo: Repository<PlatformSetting>,
   ) {}
 
   // ─── Service Plans ────────────────────────────────────────────────
@@ -143,6 +145,7 @@ export class BillingService {
     const hasRedis = dto.enableRedis || false;
     const hasRabbitmq = dto.enableRabbitmq || false;
     const hasElasticsearch = dto.enableElasticsearch || false;
+    const hasCustomDomain = dto.enableCustomDomain || false;
 
     const breakdown: { label: string; hourly: number; monthly: number; yearly: number }[] = [];
     let totalBase = 0;
@@ -184,6 +187,10 @@ export class BillingService {
           cost = hasElasticsearch ? Number(rule.unitPrice) : 0;
           label = 'Elasticsearch addon';
           break;
+        case PricingResourceType.CUSTOM_DOMAIN_ADDON:
+          cost = hasCustomDomain ? Number(rule.unitPrice) : 0;
+          label = 'Custom domain + SSL';
+          break;
       }
 
       if (cost > 0) {
@@ -222,6 +229,33 @@ export class BillingService {
     return parseFloat(memory) / (1024 * 1024 * 1024);
   }
 
+  // ─── Custom Domain Pricing (PlatformSetting) ────────────────────
+
+  async getCustomDomainPrice(): Promise<{ monthlyPrice: number }> {
+    const setting = await this.settingsRepo.findOne({
+      where: { key: 'custom_domain_monthly_price_toman' },
+    });
+    return { monthlyPrice: setting ? Number(setting.value) : 0 };
+  }
+
+  async setCustomDomainPrice(monthlyPrice: number): Promise<{ monthlyPrice: number }> {
+    let setting = await this.settingsRepo.findOne({
+      where: { key: 'custom_domain_monthly_price_toman' },
+    });
+    if (setting) {
+      setting.value = String(monthlyPrice);
+    } else {
+      setting = this.settingsRepo.create({
+        key: 'custom_domain_monthly_price_toman',
+        value: String(monthlyPrice),
+        description: 'Monthly price for custom domain addon (Toman)',
+      });
+    }
+    await this.settingsRepo.save(setting);
+    this.logger.log(`Custom domain monthly price updated: ${monthlyPrice} Toman`);
+    return { monthlyPrice };
+  }
+
   // ─── Wallet ───────────────────────────────────────────────────────
 
   async getOrCreateWallet(userId: string): Promise<Wallet> {

backend/src/billing/dto/billing.dto.ts

@@ -136,6 +136,11 @@ export class CalculateCostDto {
   @IsOptional()
   @IsBoolean()
   enableElasticsearch?: boolean;
+
+  @ApiPropertyOptional({ example: false, description: 'Enable custom domain with SSL' })
+  @IsOptional()
+  @IsBoolean()
+  enableCustomDomain?: boolean;
 }
 
 // ─── Renewal & Upgrade DTOs ─────────────────────────────────────────