fix now playing date parsing + debug panel redesign

Created by: jedmund

Summary

• Fix SimpleNowPlayingDetector to handle Date objects from @musicorum/lastfm instead of raw { uts: number } shape
• Swap unreadable trash icon for x icon in debug panel clear buttons
• Redesign debug panel: connection grid layout, compact album rows with ghost clear buttons, vertically stacked cache actions with divider
• Center header text independent of chevron icon

Test plan

• Play a track and verify now playing detection works correctly
• Open debug panel in dev, verify Now Playing tab shows key-value grid with status dot
• Verify Albums tab shows compact rows with dot-separated metadata and borderless clear buttons
• Verify Cache tab buttons stack vertically with divider separating test search from destructive actions
• Verify header text stays centered when panel is expanded