feat: extend RSS item retention from 14 to 90 days

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/services/rss.py

@@ -14,7 +14,7 @@ logger = logging.getLogger(__name__)
 
 CONTENT_MAX_CHARS = 2000
 # Keep only items from the last N days to avoid unbounded growth
-ITEM_MAX_AGE_DAYS = 14
+ITEM_MAX_AGE_DAYS = 90
 
 
 def extract_item(entry) -> dict:
@@ -135,7 +135,7 @@ async def _prune_old_items(feed_id: int) -> None:
             text("""
                 DELETE FROM rss_items
                 WHERE feed_id = :feed_id
-                  AND published_at < NOW() - INTERVAL '14 days'
+                  AND published_at < NOW() - INTERVAL '90 days'
             """).bindparams(feed_id=feed_id)
         )
         await session.commit()