List of enhancements

- Exclude Spigot searches when 'Hanger' plugins are selected, or vice versa.

- Enable downloading from both Spigot and Hanger simultaneously.

- Implement a feature to allow downloads directly from a provided URL, specifically when the search algorithm cannot find the desired plugin.

- Add an option to download the latest stable, beta or alpha versions of a plugin.

The issue groups four separate enhancements involving Spigot and Hangar searches, URL downloads, and release-channel selection. No files, tests, or entry points are named; first map the existing search and download flows, then split the requests into scoped changes with clear completion criteria for each one.

Written by the indexing model from the issue text.