Add SMS templates, prepaid IRT billing, and advertising shortcode 9000590009.

Charge ceil(len/64)*400 IRT per recipient across OTP, customer, and partner SMS; seed new businesses with 500k IRT; default partner sends to the advertising line.

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

src/customers/customers.module.ts

@@ -2,9 +2,10 @@ import { Module } from '@nestjs/common';
 import { AuthModule } from '../auth/auth.module';
 import { CustomersController } from './customers.controller';
 import { CustomersService } from './customers.service';
+import { SmsTemplatesModule } from '../sms-templates/sms-templates.module';
 
 @Module({
-  imports: [AuthModule],
+  imports: [AuthModule, SmsTemplatesModule],
   controllers: [CustomersController],
   providers: [CustomersService],
 })