Improve Now Playing Screen Gestures and Album Art Layout

[Faeb35]

Why

As discussed in #93 + #95, on big screens, swiping down on the header to close the Now Playing screen is awkward. Now you can swipe down on the album art or background instead.
Also, the album art used to sit at the very top, leaving a lot of empty space on tall or wide screens. Now it’s nicely centered (vertically in portrait, horizontally in landscape), and the glow background picks up a vibrant color from the album art for a cleaner, more immersive look. Smooth transitions make it feel extra polished.

What’s changed

• "Album art opens playlist" now defaults to false
• Album art is centered
• Glow background uses a vibrant color from the album art
• Smooth transitions when the glow changes
• Swipe gestures updated:
  • Swipe down on album art or glow background → closes Now Playing screen
  • Swipe left → next track (unchanged)
  • Swipe right → previous track (unchanged)
  • Swipe up → fast reverse (unchanged)

Test APK:
DSub2000_5.6.3-google-debug.apk.zip