Document download-client drift for the next release

[Copilot]

The Next docs were behind the current download-client surface in Maintainerr: they still described qBittorrent-only cleanup and omitted the new download_client_type contract. This updates the unreleased docs to match the current configuration, migration, and settings API behavior.

• Configuration

  • Document qBittorrent and Transmission as supported download clients
  • Add the client selector, Transmission RPC URL shape, and shared cleanup behavior
  • Clarify fallback seeding behavior when the selected client does not enforce its own seeding goal
  • Keep the shared-data safeguard described in client-agnostic terms

• Migration

  • Note the new download_client_type setting
  • Call out that upgrades default existing installs to qbittorrent

• Settings API

  • Add download_client_type to the download-client request/response contract
  • Document the reset behavior on DELETE /api/settings/download-client
  • Update connection-test semantics and error wording for the selected client
  • Document Transmission’s RPC endpoint shape alongside the existing qBittorrent WebUI URL

Example request body now documented for the settings API:

{
  "download_client_type": "qbittorrent",
  "download_client_url": "http://qbittorrent:8080",
  "download_client_username": "user",
  "download_client_password": "...",
  "download_client_delete_data": true,
  "download_client_fallback_ratio": 0.5
}

• Fixes Docs drift - updates needed for the next Maintainerr release #171

[enoch85]

@copilot Please update docs from the latest app changes.

[Copilot]

@copilot Please update docs from the latest app changes.

Updated in 2ad1a0f with the latest app-side follow-up: the Configuration docs now note that switching download client types clears the URL field because qBittorrent and Transmission use different URL shapes.