Trending feed with metric and timeframe filters

[barrydeen]

Summary

• Add trending feed sourced from nostrarchives.com relay, with metric (reactions, replies, reposts, zaps) and timeframe (today, 7d, 30d, 1y, all) filters
• Fix zombie relay connections and trending feed reconnection after app resume
• Scroll to top instantly when switching between trending feed filters

Test plan

• Switch between trending feed metrics and timeframes — verify feed updates and scrolls to top instantly
• Navigate to a note thread from trending feed and back — verify scroll position is preserved
• Background and resume the app while on trending feed — verify feed reconnects
• Switch away from trending feed and back — verify no zombie relay connections