fix: make backend local verification safe

src/tbank/tbank-connection.service.spec.ts

@@ -5,6 +5,7 @@ jest.mock('../prisma/prisma.service', () => ({
 }));
 
 import { TbankConnectionService } from './tbank-connection.service';
+import type { TbankClient } from './tbank.client';
 
 describe('TbankConnectionService', () => {
   const prisma = {
@@ -17,7 +18,9 @@ describe('TbankConnectionService', () => {
   const config = {
     getOrThrow: jest.fn(() => 'MDEyMzQ1Njc4OWFiY2RlZjAxMjM0NTY3ODlhYmNkZWY='),
   };
-  const tbank = { validateToken: jest.fn() };
+  const tbank: jest.Mocked<Pick<TbankClient, 'validateToken'>> = {
+    validateToken: jest.fn(),
+  };
   const portfolio = { invalidate: jest.fn() };
   const service = new TbankConnectionService(
     prisma as never,