Feature/apple music lyrics viewer

[HrishikeshBhandarkar]

Apple Music Lyrics Experience, Accompanist Engine & Duet Alignment

What this PR does

Brings a comprehensive Apple Music-grade lyrics experience to SimpMusic, powered by a high-performance Compose lyrics layout engine, 60Hz/120Hz monotonic smooth clock interpolation, multi-agent duet left/right alignment, dynamic typography scaling, breathing dots for instrumental breaks, and dedicated unsynced lyrics presentation.

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Highlights & Key Features

1. High-Performance Karaoke & Line-Synced Engine (KaraokeLyricsView)

   • Built on a decoupled lyrics rendering architecture with spring physics (SpringPlacementModifierNode).
   • Syllable-by-syllable text wiping for rich-synced tracks with custom cubic Bézier & Newton polynomial easing transitions.
   • Dual-line composite layout item for main vocals and background accompaniment / backing vocals.
   • Dynamic font size and layout calculator (LyricsLayoutCalculator) adapting text sizes across line lengths.

2. Apple Music Duet & Multi-Agent Alignment

   • Maps Voice 1 (v1 / lead) to Left alignment and Voice 2 (v2, v2000 / duet partner or sample vocals) to Right alignment.
   • Translations (line.translation) dynamically align with the corresponding singer (left under Voice 1, right under Voice 2).
   • Order-independent tag parsing ([bg], [v2], [v1]) in LyricsAdapter.

3. 60Hz / 120Hz Monotonic Smooth Clock Interpolation

   • Eliminates stutter caused by periodic player polling (e.g. 250ms–500ms intervals).
   • Interpolates frame-by-frame on Android's Choreographer VSync signal using withInfiniteAnimationFrameMillis.
   • Strictly monotonic: advances continuously with a gentle 8% spring catch-up, while snapping instantly on user seeks or track changes (>500ms difference).
   • Draws inside the Canvas DrawScope without recomposing the UI tree on frame updates.

4. Instrumental Breathing Dots Indicator

   • Displays animated pulsing dots during instrumental intros (>7s) and bridge interludes so users know exactly when vocals resume.

5. Display Options & Translation Support

   • Quick lyrics menu to toggle translations, romanization, and original scripts on the fly.
   • Seamlessly integrated with SharedViewModel's lyrics and AI translation pipeline.

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Commits in this PR (21 commits)

1. 6165a119 feat(core): update core submodule with lyrics timeline update time
2. 9718a7e6 feat(lyrics): add cubic bezier and newton polynomial interpolation easing curves
3. b28c66aa feat(lyrics): add spring placement modifier for fluid lyric line repositioning
4. 24441d05 feat(lyrics): add brush and color utilities for dynamic lyric text highlighting
5. b714d6f6 feat(lyrics): add multiplatform string width calculation utilities
6. 4006c801 feat(lyrics): implement breathing dots indicator for instrumental breaks and intros
7. 0ea2792d feat(lyrics): add dynamic lyrics layout and font size calculator
8. acf85e89 feat(lyrics): implement line-synced text rendering with smooth scale transitions
9. e1144e75 feat(lyrics): implement syllable-by-syllable karaoke text wipe animation
10. bcaec698 feat(lyrics): add main and accompaniment line composite layout item
11. e5398e2a feat(lyrics): implement high-performance KaraokeLyricsView composable with spring physics
12. c73e617c feat(lyrics): add LyricsAdapter domain transformer for word timestamps and backing vocals
13. b2bc105b feat(theme): add SF Pro typography and translation icon resources for Apple Music lyrics
14. 2c46b06e feat(player): add AppleMusicShared typography, styling tokens and translation menus
15. 9fb2512c feat(player): integrate KaraokeLyricsView and monotonic smooth clock in AppleMusicLyricsView
16. dcb976f9 feat(lyrics): add dedicated UnsyncedLyricsLineItem with full user scroll control
17. e503ad5d fix(lyrics): cleanly terminate active line state and auto-scroll when track reaches completion
18. bf49d3d2 build(deps): integrate accompanist lyrics-core library and configure compiler opt-ins
19. 1d1a2fd6 fix(player): initialize lyrics and translation flows before init block to prevent NPE
20. 865f79fc feat(lyrics): improve v1/v2 duet alignment and tag parsing resilience
21. 37dd62d7 chore(core): update core submodule pointer with TTML parser support

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Targeted Branch

• Base: maxrave-dev/SimpMusic:dev
• Head: HrishikeshBhandarkar/SimpMusic:feature/apple-music-lyrics-viewer

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Screen Recordings

Before (Word-by-word Old Version)	After (Apple Music Engine )
Screenrecorder-2026-09-06-21-09-51-179.mp4	Screenrecorder-2026-09-06-21-08-39-284.mp4

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Verification & Testing

• JVM Tests: :composeApp:jvmTest passed (BUILD SUCCESSFUL), verifying LyricsAdapterTest word timestamps, backing vocals handling, romanization heuristics, and v1/v2 duet placements.
• Android Compilation: :androidApp:compileDebugKotlin compiled cleanly with 0 errors.

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Checklist

• I wrote or personally reviewed every line of this change
• I tested it on Android and/or Desktop (Tested on Android device via ./gradlew :androidApp:compileDebugKotlin and JVM via ./gradlew :composeApp:jvmTest)