ios: Liquid Glass mini player, adjustable karaoke softness (1.0.7)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ios/Stemify/Playback/PlaybackManager.swift

@@ -421,11 +421,11 @@ final class PlaybackManager: StemEngineListener, @unchecked Sendable {
         return songMixes[t.ratingKey] ?? (settings.keepStemMix ? mix : [:])
     }
 
-    /// How much of the singer is left in karaoke mode. Soft is about -12 dB, a guide under your own voice.
+    /// How much of the singer is left in karaoke mode. Soft is a guide under your own voice, as quiet as settings say.
     private var karaokeMix: [String: StemSetting] {
         switch karaokeVocals {
         case .On: return [:]
-        case .Soft: return ["vocals": StemSetting(level: 0.4)]
+        case .Soft: return ["vocals": StemSetting(level: stemUntaper(Float(pow(10, Double(settings.karaokeSoftDb) / 20))))]
         case .Off: return ["vocals": StemSetting(muted: true)]
         }
     }
@@ -437,6 +437,11 @@ final class PlaybackManager: StemEngineListener, @unchecked Sendable {
         if karaoke { applyMix(karaokeMix) }
     }
 
+    func setKaraokeSoftDb(_ db: Int) {
+        settings.karaokeSoftDb = db
+        if karaoke && karaokeVocals == .Soft { applyMix(karaokeMix) }
+    }
+
     /// Turning it off puts back the song's saved mix, or the one from before, unless the mix was changed meanwhile.
     func setKaraoke(_ on: Bool) {
         guard on != karaoke else { return }