feat(mac,ios,playback,store): initial macos implementation

Packages/AmphlifyKit/Sources/Playback/PlaybackModel.swift

@@ -29,8 +29,10 @@ public enum PlaybackCommand: Codable, Sendable {
     case move(item: QueueItem.ID, after: QueueItem.ID?)
     case remove(QueueItem.ID)
     case clearUpcoming
+    case clearHistory
     case setShuffle(Bool)
     case setRepeat(RepeatMode)
+    case setVolume(Double)
 }
 
 public struct PlaybackAnchor: Hashable, Sendable {
@@ -63,6 +65,7 @@ public struct PlaybackState: Hashable, Sendable {
     public var anchor = PlaybackAnchor(position: 0, instant: .now, rate: 0)
     public var isShuffled = false
     public var repeatMode: RepeatMode = .off
+    public var volume: Double = 1
 
     public init() {}
 }
@@ -81,8 +84,10 @@ public protocol OutputEngine: Sendable {
     func pause() async
     func seek(to position: TimeInterval) async
     func stop() async
+    func setVolume(_ volume: Double) async
 }
 
 public extension OutputEngine {
     func prepare(_: QueueItem?) async {}
+    func setVolume(_: Double) async {}
 }