v0.9.1

Fixed

• Feed word counts now always computed. Items fetched from feeds but never scraped now get an ItemContent record with feed_word_count automatically. Previously, only scraped items had ItemContent, so the backfill_word_counts rake task found nothing for feed-only items.
• Backfill task creates missing ItemContent records. source_monitor:backfill_word_counts now has a two-phase approach: first creates ItemContent for items with feed content but no record, then recomputes all word counts.
• ItemContent preserved when item has feed content. Clearing scraped fields no longer destroys the ItemContent record if the item still has feed content (which provides feed_word_count).