Add Deluge integration; revamp admin Jobs & Logs UI

Introduce Deluge download client service and tests, remove obsolete rdtclient service, and update qbittorrent integration/tests and download-client interfaces/manager. Large UI refactor for admin pages: Jobs and Logs were redesigned to be responsive (mobile card views + desktop tables), improved headers, dialogs, controls, and better status/detail rendering. Also updated DownloadClient components (card, management, modal), organize-files processor, audible-series integration, and related unit tests to align with integration changes. Minor UX and accessibility tweaks, cron handling/validation adjustments, and a few formatting/cleanup fixes throughout.

tests/api/setup-tests.routes.test.ts

@@ -182,7 +182,7 @@ describe('Setup test routes', () => {
   it('rejects invalid download client type', async () => {
     const { POST } = await import('@/app/api/setup/test-download-client/route');
     const response = await POST({
-      json: vi.fn().mockResolvedValue({ type: 'deluge', url: 'http://deluge' }),
+      json: vi.fn().mockResolvedValue({ type: 'rtorrent', url: 'http://rtorrent' }),
     } as any);
     const payload = await response.json();