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/admin-settings-core.routes.test.ts

@@ -152,8 +152,8 @@ describe('Admin settings core routes', () => {
   it('rejects invalid download client types', async () => {
     const request = {
       json: vi.fn().mockResolvedValue({
-        type: 'deluge',
-        url: 'http://deluge',
+        type: 'rtorrent',
+        url: 'http://rtorrent',
       }),
     };