Feature Request: Mark available by scanning plex library or reading download

Right now I have to go in an manually mark the available check mark. This would be much easier if a scan of the plex library could be executed on a timer and show that the content is available.

The issue names no files, tests, or entry points. Start by locating where the manual availability check is stored and how Plex library or download information is read, then clarify the scheduling and matching behavior with maintainers. Done should include an automatic scan that updates availability without manual marking.

Written by the indexing model from the issue text.