[ajisth69]

Summary

This PR introduces 4 major feature additions and enhancements:

1. 10-Band Equalizer & Studio Master Clarity DSP

• 10-Band Equalizer: Sliders for 31Hz, 63Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz, 16kHz with ±12dB range and 0.1dB precision.
• Presets: Flat, Bass Boost, Studio Master, Audiophile Acoustic, Vocal Boost, EDM / Electronic, and more ported from LastWave-Native.
• Studio Master Clarity: Quick DSP enhancement targets (Air & Sheen, Vocal Forward, Sub Punch, De-Mud Midrange, Bass Tightener) applied via mpv \lavfi\ audio filters.
• Dock Integration: Equalizer trigger button added to the player dock.

2. Customizable Crossfade & Gapless Lossless Support

• Customizable Duration: 3s to 12s slider in Playback Settings with discrete 1-second divisions.
• Dual-Engine Perceptual Fader: Equal-power sin/cos volume curve across primary and standby libmpv instances.
• Early Lossless Pre-Resolve: Pre-resolves remote streams 30s before track completion to eliminate audio gap on lossless FLAC streams.
• Conflict & Crash Hardening:
  • Automatically bypasses crossfade in WASAPI Exclusive mode to prevent audio device lock contention.
  • Serializes standby player initialization through _serializedMpv\ to prevent Windows libmpv heap corruption.
  • Guards against async race conditions during pause, seek, and queue changes.
  • Synchronizes audio output devices and active equalizer DSP filters across players.

3. Floating, Movable Miniplayer

• Independent floating miniplayer supporting drag-to-move positioning anywhere on desktop.
• Integrated controls for transport, progress scrubber, and volume.

4. Static Lyrics View & Line-by-Line Sync Improvements

• Clean presentation for un-synced lyrics without plain text clutter.
• Enhanced line-by-line matching and multi-provider fallback.

Verification

• \dart analyze lib\ passed with 0 errors and 0 warnings.