fix: add missing mocks for off-service.js and searchOTC in backend tests

The backend test was hanging in CI because server.js imports off-service.js
which pulls in redis-client.js. Without a mock, it tries to connect to Redis
at import time, hanging indefinitely in CI where no Redis server exists.

Also added the missing searchOTC mock for cima-service.js to fix the
SyntaxError from the export mismatch.

apps/backend/__tests__/server.test.js

@@ -3,6 +3,12 @@ import { jest } from '@jest/globals'
 jest.unstable_mockModule('../cima-service.js', () => ({
   searchMedicines: jest.fn(async () => []),
   getMedicineDetails: jest.fn(async () => null),
+  searchOTC: jest.fn(async () => []),
+}))
+
+jest.unstable_mockModule('../off-service.js', () => ({
+  searchBabyProducts: jest.fn(async () => []),
+  getBabyProductDetails: jest.fn(async () => null),
 }))
 
 jest.unstable_mockModule('../farmacias-webhook-import.js', () => ({