- Extend DesktopClientReleaseCheckResponse with platform, arch, and channel fields.
- Introduce DesktopClientDownloadableRelease and DesktopClientDownloadableReleaseListResponse interfaces for managing downloadable releases.
- Implement ListDownloadable method in DesktopClientReleaseService to retrieve downloadable releases based on the specified channel.
- Update DesktopClientReleaseCheckResult to include platform, arch, and channel information.
- Add resolveInstallerDownloadURL method to handle download URL resolution for releases.
- Create new endpoint in DesktopReleaseHandler for listing downloadable releases.
- Update router to include the new downloadable releases route.
- Enhance tests to cover the new functionality for resolving download URLs and listing downloadable releases.