feat(payment): integrate CAC Bank OTP payments into freight flows

CAC Bank is an OTP debit with no redirect and no webhook: initiate SMSes a
code to the payer's mobile, and the charge only settles when that code is
confirmed. The payment service already spoke it (passenger uses it); the
freight side had the enum values but none of the flow.

API:
- PaymentClientService.confirmOtp forwards the code to
  POST /payments/intents/:id/confirm, mapping 400/404 to BadRequest so a
  mistyped code stays retryable instead of surfacing as a gateway failure.
- PaymentService.confirmOtp is keyed by the LOCAL intent id (the invoice's
  paymentId) rather than the domain reference, so the right invoice settles
  when several share a booking. On success billing settles the invoice.
- payInvoice rejects CAC_BANK without payerAccount before calling the
  gateway, and no longer runs the demo auto-settle for a COLLECT_OTP intent
  (it is not paid until the payer confirms).
- POST /billing/my-invoices/:id/confirm — ownership-checked, and since
  warehouse fee invoices are central invoices it covers those too.

Portal:
- useInvoicePayment owns the whole flow (initiate, redirect-or-OTP, confirm)
  and replaces the five near-identical pay mutations at the call sites.
- PaymentMethodModal gains the CAC Bank option, the payer mobile field, and
  the OTP step. Click-outside is disabled there so a stray click cannot drop
  the payer out of a live OTP window.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/edr-freight-api/src/modules/billing/dto/pay-invoice.dto.ts

@@ -1,5 +1,13 @@
-import { ApiPropertyOptional } from "@nestjs/swagger";
-import { IsIn, IsOptional, IsString } from "class-validator";
+import { ApiProperty, ApiPropertyOptional } from "@nestjs/swagger";
+import { IsIn, IsNotEmpty, IsOptional, IsString } from "class-validator";
+
+/** OTP submitted for a COLLECT_OTP provider (CAC Bank). */
+export class ConfirmOtpDto {
+  @ApiProperty({ description: "One-time password SMSed by the bank." })
+  @IsString()
+  @IsNotEmpty()
+  otp!: string;
+}
 
 /** Gateway options for paying an invoice from the customer portal. */
 export class PayInvoiceDto {