Add Deluge download client support

[Algorant]

Summary

Adds Deluge Web JSON-RPC as a supported download client.

Fixes #240.

Changes

Added

• DelugeAdapter implementing Listenarr download-client operations via Deluge Web JSON-RPC:
  • connection/authentication check
  • add torrent
  • remove torrent
  • queue/item monitoring
  • import item lookup
  • download status polling
• Named Deluge HttpClient registration with cookie support for Deluge Web sessions.
• Deluge adapter registration with IDownloadClientAdapterFactory.
• Deluge frontend configuration support:
  • client type option
  • default port 8112
  • optional URL base/reverse-proxy prefix
  • category/label guidance
• README supported-client documentation for Deluge.
• Backend adapter tests covering lifecycle status mapping, category filtering, daemon connection, external torrent id matching, and completed/imported status preservation.

Changed

• Download client type definitions/configuration now include deluge.
• Download client settings UI now lists Deluge alongside qBittorrent, Transmission, SABnzbd, and NZBGet.

Fixed

• Deluge monitor/import matching uses the external torrent id/hash instead of the Listenarr client/config id.

Testing

• dotnet test tests/Listenarr.Tests.csproj --filter FullyQualifiedName~DelugeAdapterTests
  • Passed: 12/12
• cd fe && npm run type-check && npm run lint:check
  • Passed
• Push hook also ran:
  • backend format check
  • frontend type check
  • frontend tests: 74 passed, 1 skipped test file; 378 tests passed

Notes

• Branch is based on latest canary.
• Deluge label/category support requires the Deluge Label plugin to be enabled.
• UI change is limited to download-client configuration fields; screenshots can be added if maintainers want visual confirmation.

Checklist

• Code follows project style guidelines
• Self-review of code completed
• Comments added for complex logic where useful
• Tests added/updated
• Relevant backend tests pass
• Frontend type check and lint pass
• Documentation updated in README supported clients
• Rebased on latest canary

[Algorant]

This is my attempt at adding deluge as a download client. It is currently working in my homelab on my fork. Open to feedback/suggestions.

Note: my agent pushed this pr when I meant to keep it as a draft. Switched it to draft after creation.

[therobbiedavis]

@Algorant I know this is still in draft but there was a large backend refactor that was just merged. This will need to be rebased.

[Algorant]

Sure no problem! I've been following canary. I'll get it sorted.

[therobbiedavis]

Heads up: PR #599 changes the download-client architecture and should be treated as the new base for additional clients.

Deluge should be rebased on #599 and refactored to match the new boundaries: thin adapter facade, client-specific infrastructure workflows, GetQueueAsync(client) as the full queue snapshot path, GetQueueAsync(client, ids) as targeted monitor polling, gateway-owned remote path mapping, and client-specific import item resolution before the processor decides a source is unavailable.

[Algorant]

Makes sense thank you!