refactor(core): Simplify ExternalSecretsProxy setup and move it to core (#16021)

packages/cli/src/controllers/oauth/__tests__/oauth1-credential.controller.test.ts

@@ -6,7 +6,7 @@ import { Container } from '@n8n/di';
 import Csrf from 'csrf';
 import type { Response } from 'express';
 import { captor, mock } from 'jest-mock-extended';
-import { Cipher, type InstanceSettings } from 'n8n-core';
+import { Cipher, type InstanceSettings, ExternalSecretsProxy } from 'n8n-core';
 import type { IWorkflowExecuteAdditionalData } from 'n8n-workflow';
 import nock from 'nock';
 
@@ -19,7 +19,6 @@ import { BadRequestError } from '@/errors/response-errors/bad-request.error';
 import { NotFoundError } from '@/errors/response-errors/not-found.error';
 import { ExternalHooks } from '@/external-hooks';
 import type { OAuthRequest } from '@/requests';
-import { SecretsHelper } from '@/secrets-helpers.ee';
 import * as WorkflowExecuteAdditionalData from '@/workflow-execute-additional-data';
 import { mockInstance } from '@test/mocking';
 
@@ -28,7 +27,7 @@ jest.mock('@/workflow-execute-additional-data');
 describe('OAuth1CredentialController', () => {
 	mockInstance(Logger);
 	mockInstance(ExternalHooks);
-	mockInstance(SecretsHelper);
+	mockInstance(ExternalSecretsProxy);
 	mockInstance(VariablesService, {
 		getAllCached: async () => [],
 	});