Fixed 5 critical gaps in the download orchestrator where lidarr was
missing from client loops: get_all_downloads, get_download_status,
cancel_download fallback, clear_all_completed_downloads, and
cancel_all_downloads. Without these, lidarr downloads were invisible
to the UI, couldn't be cancelled, and accumulated in memory.
Also: error messages now visible in download list (appended to
filename on error state), removed "(Development)" label from UI.
6ca3f3b070