global settings
- root storage directory
- config settings
- history
per feed
- URL
- storage directory
- feed name (derive from RSS)
- deletion rules
- file limit
- date limit
- size limit
- scan rules
- scan interval
- clock-based ("5 minutes after hour", "Tuesdays")
- last scan date/time
- last failure reason
- last successful date/time
- count of consecutive failures