- Fix handle_info(:refresh_spots) to use start_async instead of blocking
LiveView process on DB fetches
- Add require Logger to fix pre-existing compiler warning
- Make band counts clickable: clicking a band filters table to that band's
last 100 spots; clicking again clears the filter
- Highlight active filter badge, show Clear filter link when filtered
- Update subtitle and empty state dynamically based on filter
- Filter persists across auto-refresh (60s)
- Add 5 test cases for band filtering behavior
