Implement IMPS fund transfer via initiate and verify-otp

Initiate runs the IMPS name inquiry and sends an OTP; verify-otp sends
ReqPay. The result screen now distinguishes success, failure and
pending reconciliation. The payer is temporarily fixed to the test
account 002002000100019, and the to-mobile form no longer blocks on
mobile/MMID format.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/services/api/cbsErrors.test.ts

@@ -9,9 +9,9 @@ import {
 } from './cbsErrors';
 
 describe('error code catalogue', () => {
-  it('covers all 46 documented codes, with no duplicates', () => {
-    expect(CBS_ERROR_CODES).toHaveLength(46);
-    expect(new Set(CBS_ERROR_CODES).size).toBe(46);
+  it('covers all 48 documented codes, with no duplicates', () => {
+    expect(CBS_ERROR_CODES).toHaveLength(48);
+    expect(new Set(CBS_ERROR_CODES).size).toBe(48);
   });
 
   it('does not invite a retry when the bank withholds a balance', () => {

src/services/api/cbsErrors.ts

@@ -51,6 +51,8 @@ export const CBS_ERROR_CODES = [
   'SMS_DELIVERY_FAILED',
   'OTP_PROVIDER_UNAVAILABLE',
   'CONNECTOR_UNAVAILABLE',
+  'IMPS_REQUEST_REJECTED',
+  'TRANSFER_NOT_AWAITING_OTP',
 ] as const;
 
 export type CbsErrorCode = (typeof CBS_ERROR_CODES)[number];
@@ -256,7 +258,7 @@ const ERROR_COPY: Record<AnyErrorCode, ErrorCopy> = {
   },
   OTP_ATTEMPTS_EXCEEDED: {
     title: 'Too many wrong codes',
-    description: 'Start registration again to get a new code.',
+    description: 'Start again to get a new code.',
   },
   INTERNAL_ERROR: {
     title: 'Something went wrong at the bank',
@@ -282,6 +284,15 @@ const ERROR_COPY: Record<AnyErrorCode, ErrorCopy> = {
     title: 'Payee checks are unavailable',
     description: 'This is a server configuration issue, not a problem with the details you entered.',
   },
+  IMPS_REQUEST_REJECTED: {
+    title: 'The payment network refused the request',
+    description: 'Nothing was sent. Please try again in a moment.',
+    retryable: true,
+  },
+  TRANSFER_NOT_AWAITING_OTP: {
+    title: 'This transfer is already finished',
+    description: 'It is no longer waiting for a code, so nothing was sent again. Check your transactions for its outcome.',
+  },
   MMID_ALLOCATION_FAILED: {
     title: 'We could not finish setting up your accounts',
     description: 'Please try again shortly.',

src/services/api/endpoints.ts

@@ -69,6 +69,15 @@ export const endpoints = {
     save: '/beneficiaries',
     validate: '/beneficiaries/validate',
   },
+  /**
+   * IMPS transfers, in two steps. `initiate` runs the name inquiry and sends an
+   * OTP but moves no money; `verifyOtp` consumes the OTP and sends ReqPay. The
+   * server never sends ReqPay before a verified OTP, and never retries it.
+   */
+  fundTransfers: {
+    initiate: '/fund-transfers/initiate',
+    verifyOtp: (transferId: string) => `/fund-transfers/${transferId}/verify-otp`,
+  },
   dashboard: {
     summary: '/dashboard/summary',
   },