feat(mobile): now playing indicator with animated eq bars

[dylanjeffers]

Summary

• Adds a now-playing indicator to track rows in playlist / track list views on mobile
• Active track row now uses a subtle purple background tint (rgba(130,86,220,0.07)) and a purple title color (#8256DC)
• While the track is playing, the artwork shows an animated equalizer overlay (4 bars, #CC5DE8, height ~4→18px, staggered durations / delays) using React Native Animated with useNativeDriver: false
• New reusable AnimatedEqBars component lives next to TrackArtwork in packages/mobile/src/components/track-list/

The paused-but-active state (active row, not currently playing) still shows the existing play-icon overlay — only the playing state swaps in the equalizer animation.

Files changed

• packages/mobile/src/components/track-list/AnimatedEqBars.tsx (new)
• packages/mobile/src/components/track-list/TrackArtwork.tsx
• packages/mobile/src/components/track-list/TrackListItem.tsx

Test plan

• Open a playlist on iOS, tap a track to play it
  • That row gets a purple tint and the title turns purple
  • Bars animate over the artwork (4 bars, anchored bottom-center, staggered)
• Pause playback
  • Row stays purple-tinted; artwork shows the play icon (no animation)
• Skip to another track in the same list
  • Indicator follows to the new row; old row reverts to default styling
• Same checks on Android
• Reorderable playlist (drag mode): tinted row still renders correctly
• Locked / unlisted / deleted tracks remain unaffected when not active

[changeset-bot]

⚠️ No Changeset found

Latest commit: 9fa9faa

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR