fix: convert all test files from jest to vitest and fix QBittorrentClient import

- Convert RTorrentClient.test.js to use vi.mock() instead of jest.mock()
- Convert QBittorrentClient.test.js to use vi.mock() instead of jest.mock()
- Convert SABnzbdClient.test.js to use vi.mock() instead of jest.mock()
- Convert TransmissionClient.test.js to use vi.mock() instead of jest.mock()
- Convert downloadClients.test.js to use vi.mock() instead of jest.mock()
- Convert integration/downloadClients.test.js to use vi.mock() instead of jest.mock()
- Fix legacy qbittorrent.test.js to import QBittorrentClient from new location
- Add getRtorrentInstances mock to downloadClients.test.js
- Add RTORRENT_INSTANCES to integration test environment variables

tests/unit/clients/SABnzbdClient.test.js

@@ -1,11 +1,12 @@
 // Copyright (c) 2026 Gordon Bolton. MIT License.
 const SABnzbdClient = require('../../../server/clients/SABnzbdClient');
 const axios = require('axios');
+const { vi } = require('vitest');
 
 // Mock axios
-jest.mock('axios');
-jest.mock('../../../server/utils/logger', () => ({
-  logToFile: jest.fn()
+vi.mock('axios');
+vi.mock('../../../server/utils/logger', () => ({
+  logToFile: vi.fn()
 }));
 
 describe('SABnzbdClient', () => {
@@ -23,7 +24,7 @@ describe('SABnzbdClient', () => {
     client = new SABnzbdClient(mockConfig);
     
     // Clear all mocks
-    jest.clearAllMocks();
+    vi.clearAllMocks();
   });
 
   describe('Constructor', () => {
@@ -42,7 +43,7 @@ describe('SABnzbdClient', () => {
         data: { version: '3.6.1' }
       };
       
-      client.makeRequest = jest.fn().mockResolvedValue(mockResponse);
+      client.makeRequest = vi.fn().mockResolvedValue(mockResponse);
       
       const result = await client.testConnection();
       
@@ -51,7 +52,7 @@ describe('SABnzbdClient', () => {
     });
 
     it('should handle connection test failure', async () => {
-      client.makeRequest = jest.fn().mockRejectedValue(new Error('Connection failed'));
+      client.makeRequest = vi.fn().mockRejectedValue(new Error('Connection failed'));
       
       const result = await client.testConnection();
       
@@ -244,7 +245,7 @@ describe('SABnzbdClient', () => {
         }
       };
 
-      client.makeRequest = jest.fn()
+      client.makeRequest = vi.fn()
         .mockResolvedValueOnce(mockQueueResponse)
         .mockResolvedValueOnce(mockHistoryResponse);
 
@@ -258,7 +259,7 @@ describe('SABnzbdClient', () => {
     });
 
     it('should handle API errors gracefully', async () => {
-      client.makeRequest = jest.fn().mockRejectedValue(new Error('API Error'));
+      client.makeRequest = vi.fn().mockRejectedValue(new Error('API Error'));
 
       const downloads = await client.getActiveDownloads();
 
@@ -280,7 +281,7 @@ describe('SABnzbdClient', () => {
         }
       };
 
-      client.makeRequest = jest.fn().mockResolvedValue(mockResponse);
+      client.makeRequest = vi.fn().mockResolvedValue(mockResponse);
 
       const status = await client.getClientStatus();
 
@@ -294,7 +295,7 @@ describe('SABnzbdClient', () => {
     });
 
     it('should handle status request errors', async () => {
-      client.makeRequest = jest.fn().mockRejectedValue(new Error('Status error'));
+      client.makeRequest = vi.fn().mockRejectedValue(new Error('Status error'));
 
       const status = await client.getClientStatus();