feat: billing v2 — runtime-based plans, English UI, payment flow

- ServicePlan now has 'runtime' field (nodejs/laravel/wordpress)
- Admin billing page: Application Type dropdown, English UI, Toman prices
- calculateCost filters active plans by matching runtime
- Wallet page: English UI, payment gateway integration (Pay Now button)
- Deploy page Review step: billing cycle selector (hourly/monthly/yearly),
  payment method choice (wallet or payment gateway), Pay & Deploy button
- Payment gateway endpoints: POST /billing/gateway/initiate + /verify
  (simulated — ready for Zarinpal/IDPay integration)
- Deploy requires payment: wallet deduction or gateway charge before deploy

backend/src/billing/billing.service.ts

@@ -28,6 +28,7 @@ export class BillingService {
   async createPlan(dto: CreateServicePlanDto): Promise<ServicePlan> {
     const plan = this.planRepo.create({
       name: dto.name,
+      runtime: dto.runtime,
       description: dto.description,
       billingCycle: dto.billingCycle,
     });
@@ -47,6 +48,7 @@ export class BillingService {
     if (!plan) throw new NotFoundException('Plan not found');
 
     if (dto.name !== undefined) plan.name = dto.name;
+    if (dto.runtime !== undefined) plan.runtime = dto.runtime;
     if (dto.description !== undefined) plan.description = dto.description;
     if (dto.billingCycle !== undefined) plan.billingCycle = dto.billingCycle;
     if (dto.isActive !== undefined) plan.isActive = dto.isActive;
@@ -101,7 +103,12 @@ export class BillingService {
     yearly: number;
     breakdown: { label: string; hourly: number; monthly: number; yearly: number }[];
   }> {
-    const plans = await this.findActivePlans();
+    // Only use active plans that match the requested runtime
+    const plans = await this.planRepo.find({
+      where: { isActive: true, runtime: dto.runtime as any },
+      relations: ['pricingRules'],
+    });
+
     if (plans.length === 0) {
       return { hourly: 0, monthly: 0, yearly: 0, breakdown: [] };
     }
@@ -140,7 +147,7 @@ export class BillingService {
       switch (rule.resourceType) {
         case PricingResourceType.BASE_FEE:
           cost = Number(rule.unitPrice);
-          label = 'هزینه پایه';
+          label = 'Base fee';
           break;
         case PricingResourceType.CPU_PER_CORE:
           cost = cpuCores * replicas * Number(rule.unitPrice);